PTA-算法设计与分析
7-1 c++(g++)
#include<bits/stdc++.h>
using namespace std;
long max3(long a,long b,long c)
{ if(a<b) a=b;
if(a>c) return a;
else return c;
}
long maxSubSum(int a[],int left,int right)
{ int i,j;
long maxLeftSum,maxRightSum;
long maxLeftBorderSum,leftBorderSum;
long maxRightBorderSum,rightBorderSum;
if(left==right)
{ if(a[left]>0)
return a[left];
else
return 0;
}
int mid=(left+right)/2;
maxLeftSum=maxSubSum(a,left,mid);
maxRightSum=maxSubSum(a,mid+1,right);
maxLeftBorderSum=0,leftBorderSum=0;
for(i=mid;i>=left;i--)
{ leftBorderSum+=a[i];
if(leftBorderSum>maxLeftBorderSum)
maxLeftBorderSum=leftBorderSum;
}
maxRightBorderSum=0,rightBorderSum=0;
for(j=mid+1;j<=right;j++)
{ rightBorderSum+=a[j];
if(rightBorderSum>maxRightBorderSum)
maxRightBorderSum=rightBorderSum;
}
return max3(maxLeftSum,maxRightSum,maxLeftBorderSum+maxRightBorderSum);
}
int main()
{ int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++)
{ cin>>a[i];
}
cout<<maxSubSum(a,0,n-1)<<endl;
}
7-2 c++(g++)
#include<bits/stdc++.h>
using namespace std;
int n;
int flag[10000000+1];
int count(int n) {
int cnt = 0;
flag[2] = 1;
for (int i = 3; i <= n; ++i) {
flag[i++] = 1; // 奇数位
flag[i] = 0; // 偶数位直接过滤
}
for (int i = 3; i <= sqrt(n*1); ++i) {
if (flag[i] != 1) continue;
for (int j = i*i; j <= n; j += i) {
// 将倍数转换为加法
flag[j] = 0;
}
}
for (int i = 1; i <= n; ++i)
cnt += flag[i];
return cnt;
}
int main()
{ cin>>n;
cout<<count(n);
}
7-3 c++(g++)
#include <stdio.h>
#include <string.h>
int main()
{
char a[6],b[81];
int i,j,k,m,n,c[6]={0};
while(gets(a)&&a[0]!='#')
{
gets(b);
m=strlen(a);
n=strlen(b);
for(i=0;i<m;i++)
{
c[i]=0;
for(j=0;j<n;j++)
{
if(a[i]==b[j])
c[i]++;
}
}
for(i=0;i<m;i++)
printf("%c %d\n",a[i],c[i]);
}
return 0;
}
7-4 c++(g++)
#include<stdio.h>
long long d[102];
int main()
{
int T,n,i;
scanf("%d",&T);
for(i=0;i<102;i++) d[i]=0;
d[1]=0;
d[2]=1;
for(i=3;i<=100;i++)
d[i]=((i-1)*(d[i-1]%1000000007+d[i-2]%1000000007))%1000000007;
/*
right now: MOD=1000000007;
for(i=3;i<=100;i++)
{
a[i]=a[i-1]+a[i-2];
a[i]%=MOD;
a[i]*=i-1;
a[i]%=MOD;
}
*/
while(T--)
{
scanf("%d",&n);
printf("%lld\n",d[n]);
}
return 0;
}
7-5 c++(g++)
#include"iostream"
#include"cstdio"
#include"cstring"
using namespace std;
const int maxn = 50;
int num[maxn + 1];
int c1[maxn + 1], c2[maxn + 1];
int main(){
int T;
scanf("%d",&T);
while(T --){
for(int i = 1;i <= 26;i ++)
scanf("%d", &num[i]);
memset(c1, 0, sizeof c1);
memset(c2, 0, sizeof c2);
for(int i = 0;i <= num[1];i ++)
c1[i] = 1;
for(int i = 2;i <= 26;i ++){ //共有26个多项式
if(num[i] == 0) continue;
for(int j = 0;j <= maxn;j ++){ //共有maxn+1项
for(int k = 0;k <= num[i] && j + k*i <= maxn;k ++)
c2[j + k*i] += c1[j];
}
for(int j = 0;j <= maxn;j ++){
c1[j] = c2[j];
c2[j] = 0;
}
}
int sum = 0;
for(int j = 1;j <= maxn;j ++)
sum += c1[j];
printf("%d\n",sum);
}
return 0;
}
7-6 c++(g++)
#include <iostream>
using namespace std;
const int MAXA=100;
int a[MAXA];
int max(int x, int y)
{
if (x < y)
{
cout << "max(" << x << "," << y << ")=" << y << " ";
return y;
}
else
{
cout << "max(" << x << "," << y << ")=" << x << " ";
return x;
}
}
/**
* @brief Use digui to find the maxnumber of the array
* arraymax(a,n)=max(a[0],a[1]); n==2;
* arraymax(a,n)=max(arraymax(n-2),a[n-1]); other situation;
*
* @param a
* @param n sizeof(a)/sizeof(a[0])
*
* @return the number_value of array
*/
int arraymax(int a[], int n)
{
int b;
if (n == 1)
return max(a[0], a[1]);
else if(n>1&&n<=30)
{ b=arraymax(a,n-1);
return max(b, a[n]);
}
}
int main()
{
int n;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> a[i];
}
cout << arraymax(a, n-1) << endl;//0~n-1
return 0;
}
7-7 c++(g++)
#include<iostream>
#include<algorithm>
using namespace std;
/**
* recursion && Division algorithm
*/
/**
* @brief recursion algroithm
*
* gcd(x,y)=y; x%y=0;
* gcd(x,y)=disp;if(x%y>0)gcd(x%y,min(x,y)) else gcd(max(x,y),min(x,y)); other sitation;
*
* @param x
* @param y
* @return the number_value
*/
int gcd(int x,int y)
{
// int a,a1,a2,a3,a4;
if(x%y==0)
{ cout<<"gcd("<<x<<","<<y<<") ";
return y;
}
else
{
cout<<"gcd("<<x<<","<<y<<") ";
// a=x%y;
// a1=max(x,y);
// a2=min(x,y);
// a3=min(a,y);
// a4=min(x,a)
if(x/y>0)
return gcd(y,x%y);
else
return gcd(max(x,y),min(x,y));
}
}
int main()
{
int x,y;
cin>>x;cin>>y;
cout<<gcd(x,y);
}
7-8 c++(g++)
#include <stdio.h>
void swap(int a[], int i, int j)
{
// 交换数组a中元素i与元素j的值
int tmp;
tmp = a[i];
a[i] = a[j];
a[j] = tmp;
}
int partition(int a[], int lo, int hi)
{
int i = lo-1, pivot = a[lo];
swap(a, lo, hi);
while(lo<hi)
{
// 循环开始的时候i指向的是小于pivot的最后的一个位置
if(a[lo] < pivot)
{
i ++;
swap(a, i, lo);
}
lo ++;
}
i ++;
swap(a, i, hi);
return i;
}
int find(int a[], int left, int right, int k)
{
int index;
index = partition(a, left, right);
if(index == k)
return a[index];
else if(index < k)
return find(a, index+1, right, k);
else
return find(a, left, right-1, k);
}
int main()
{
int a[10000];
int n, k, i;
scanf("%d", &n);
scanf("%d", &k);
for(i=0; i<n; i++)
scanf("%d", &a[i]);
printf("%d\n", find(a, 0, n-1, k-1));
}
7-9 c++(g++)
#include<bits/stdc++.h>
using namespace std;
void swap(int a,int b)
{ int tmp;
if(a<b)
{ tmp=a;
a=b;
b=tmp;
}
}
int num(int n,int a[])
{ int count=0;
for(int j=0;j<n-1;j++)
for(int i=0;i<=n-2;i++)
{ if(a[i]>a[i+1])
{ swap(a[i],a[i+1]);
count++;
break;
}
}
return count;
}
// i==2
// 0 1 d 1 2 2083 s 2 3 2803 s
int main()
{ int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++)
{ cin>>a[i];
}
cout<<num(n,a);
}
7-10 c++(g++)
#include<stdio.h>
#include<string.h>
int main()
{
int n,i,j,max=0;//max为所用箱子的数目
int a[1005];//用来接收物品的
int b[1005];//即用来描述物品，又用来记录装物品的箱子（看完代码后自然会理解）
int pox[10005];//箱子的位置
memset(pox,-1,sizeof(pox));
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
b[i]=a[i];
}
pox[0]=0;//将箱子的位置初始化为0，是为了与数组的下标匹配，更方便标记位置
for(i=1;i<n;i++)
{
for(j=0;j<i;j++)
{
if(a[i]+b[j]<=100)
{
b[j]=b[j]+a[i];//将两个物品放在一个箱子中
b[i]=0;//用于同步物品的信息
pox[i]=j;
break;
}
else
{
pox[i]=i;
}
}
}
for(i=0;i<n;i++)
{
if(pox[i]>max)
{
max=pox[i];
}
}
for(i=0;i<n;i++)
{
printf("%d %d\n",a[i],pox[i]+1);
}
printf("%d",max+1);
return 0;
}
7-11 c++(g++)
#include <iostream>
using namespace std;
int a[1010];
int main()
{
int n, k, i, h = 0, j = 0, b;
cin >> n >> k;
b = n;
for (i = 0; i <= k; i++) //共有k+1个数，因为它们都是表示一个性质的，所以可以一起处理
cin >> a[i];
for (i = 0; i <= k; i++)
if (a[i] > n)
{
cout << "No Solution!\n"; //只要有一段路程大于n就无法到达
j = 1; //此处标记
break;
}
// else
{
for (i = 1; i <= k; i++)
{
b -= a[i - 1];
if (b < a[i])
{
h++;
b = n;
}
}
}
if (!j) //利用标记法,要不然会错过h=0时的情况导致一个测试点无法通过（5分）
cout << h << endl;
return 0;
}
7-12 c++(g++)
#include<bits/stdc++.h>
using namespace std;
void greedy(int n,int start[],int end[]);
int a[1000],b[1000];
int main()
{
int n;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>a[i]>>b[i];
}
sort(a,a+n); //对开始时间进行上升排序
sort(b,b+n); //对结束时间进行上升排序
greedy(n,a,b); //调用函数求最小会场数
}
void greedy(int n,int start[],int end[])
{
int j=0;
int count=0;
for(int i=0;i<n;i++)
{
if(start[i]<end[j]){
count++;//如果开始时间小于结束时间则另开辟一个会场
}else{
j++;//否则和下一个结束时间进行比较
}
}
printf("%d",count);
}
7-13 c++(g++)
#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
int k;
cin>>k;
int a[k],b[k];
for(int i=0;i<k;i++)
{
cin>>a[i];
}
sort(a,a+k);
for(int i=k-1,j=0;i>=0;i--,j++)
{
b[j]=a[i];
}
int sum1=0,sum2=0;
for(int i=0;i<k-1;i++)
{
a[i+1]=a[i]+a[i+1];
sum1+=a[i+1];
sort(a+i,a+k);
}
for(int j=0;j<k-1;j++)
{
b[j+1]=b[j]+b[j+1];
sum2+=b[j+1];
}
cout<<sum2-k+1<<" ";
cout<<sum1-k+1<<endl;
return 0;
}
7-14 c++(g++)
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <set>
using namespace std;
typedef struct ab{
int s;
int f;
};
int cmp(ab a,ab b)
{
return a.f<b.f;
}
int main()
{
int n;
ab x[110];
while(~scanf("%d",&n))
{
if(n==0)
{
break;
}
for(int i=0;i<n;i++)
{
scanf("%d %d",&x[i].s,&x[i].f);
}
sort(x,x+n,cmp);
int sum=1;
int fina=x[0].f;
for(int i=1;i<n;i++)
{
if(x[i].s>=fina)
{
sum++;
fina=x[i].f;
}
}
printf("%d\n",sum);
}
return 0;
}
7-15 c++(g++)
#include<iostream>
using namespace std;
int a[12][12] = {0,1,0,0,0,1,1,1,0,1,0,1,
0,0,0,1,0,0,0,0,1,0,0,1,
0,1,0,1,0,1,1,1,0,1,0,0,
0,1,0,0,0,0,0,1,0,0,1,1,
0,0,0,0,1,0,0,0,0,0,0,0,
0,0,1,0,0,0,1,0,0,0,1,0,
0,0,1,0,0,0,0,0,1,0,0,0,
1,0,0,1,0,1,0,0,0,1,0,1,
0,0,1,0,1,0,1,0,1,0,0,0,
0,0,0,0,0,1,0,0,0,1,1,0,
0,0,0,0,0,1,0,0,0,0,0,0,
0,1,0,1,0,0,0,1,0,1,0,0};
int x1, x2, y1, y2, min1 = 210000000, t = 0, b[12][12] = {0}, c[12][12] = {0};
int ff(int x, int y, int k)//当前的位置，k是当前的步数；
{
int a1, a2, a3, a4;
if(x < 0 || y < 0 ||x >= 12 || y >= 12)
{
return 0;
}
else
{
if(x == x2 && y == y2)
{
t++;
if(min1 > k) min1 = k;
return 1;
}
else
{
if(k >= min1) return 1;
if(a[x][y] == 0)
{
if(b[x][y] == 0)
{
if(c[x][y] == 0)
{
b[x][y] = 1;
a1 = ff(x+1, y, k+1);
a2 = ff(x, y+1, k+1);
a3 = ff(x-1, y, k+1);
a4 = ff(x, y-1, k+1);
b[x][y] = 0;
if(a1 == 0&&a2 == 0&&a3 == 0&&a4 == 0)
{
c[x][y] = 1;
return 0;
}
else return 1;
}
return 0;
}
else return 1;
}
else
{
return 0;
}
}
}
}
int main()
{
int i, j;
cin>>x1>>y1>>x2>>y2;
if(a[x2][y2] == 1) cout<<"10000";
else
{
ff(x1, y1, 1);
if(t == 0) cout<<"10000";
else cout<<min1-1;
}
return 0;
}
7-16 c++(g++)
#include<iostream>
using namespace std;
int a[10000], n, t, b[10000] = {0}, z = 0;
int c[10000];
void print(int k)
{
int i;
z++;
for(i = 1; i <= k; i++)
{
cout<<c[i]<<" ";
}
cout<<endl;
}
int ff()
{
int i = 1, sum = 0, j = 1;
while(i > 0)
{
if(b[i] == 0)
{
b[i] = 1;
sum += a[i];
c[j] = a[i];
j++;
i++;
if(sum == t) return j;
if(sum > t)
{
sum -= a[i-1];
b[i-1] = 0;
j--;
}
if(i > n)
{
i = n - 1;
if(b[n] == 1)
{
sum -= a[n];
b[n] = 0;
j--;
}
while(b[i] == 0)
{
i--;
if(i < 0) return 0;
}
j--;
sum -= a[i];
b[i] = 0;
i++;
}
}
}
return 0;
}
int main()
{
int i, j, tol = 0;
cin>>n>>t;
for(i = 1; i <= n; i++)
{
cin>>a[i];
tol += a[i];
}
if(tol >= t)
{
j = ff();
if(j)
{
print(j-1);
}
else cout<<"No Solution!";
}
else cout<<"No Solution!";
return 0;
}
7.17 c++(g++)
#include<iostream>
#include<cstdlib>
using namespace std;
int n, a[1000], x, b[100] = {0}, Min = 2100000000;
int compare(void const * q, void const * p)
{
return *(int *)q - *(int *)p;
}
int ff(int k)
{
int i, Max = 0, t;
if(k <= n)
{
for(i = 1; i <= x; i++)
{
if((b[i] + a[k]) > Min)
return 0;
b[i] += a[k];
t = ff(k+1);
//if(t == 0) return 0;
b[i] -= a[k];
}
}
if(k > n)
{
for(i = 1; i <= x; i++)
{
if(b[i] > Max) Max = b[i];
}
if(Min > Max) Min = Max;
}
}
int main()
{
int i;
cin>>n>>x;
for(i = 1; i <= n; i++)
{
cin>>a[i];
}
qsort(&a[1], n, sizeof(int), compare);
ff(1);
cout<<Min;
return 0;
}
7.18 c++(g++)
#include<iostream>
using namespace std;
int a[10005], n, t, b[10005] = {0}, z = 0;
void print(int k)
{
int i;
z++;
for(i = 1; i < k; i++)
{
if(i == 1) cout<<b[i];
else cout<<" "<<b[i];
}
cout<<endl;
}
void ff(int k, int w, int num)//k是前一个数的下表，w是当前要存入的下标 ，num是当前总数
{
int i;
if(num <= t)
{
if(num == t)
{
print(w);
}
else
{
for(i = k+1; i <= n; i++)
{
b[w] = a[i];
ff(i, w+1, num+a[i]);
}
}
}
}
int main()
{
int i;
cin>>n;
for(i = 1; i <= n; i++)
cin>>a[i];
cin>>t;
ff(0, 1, 0);
if(z == 0) cout<<"None";
return 0;
}
7.19 c++(g++)
#include <stdio.h>
#define inf 0x3f3f3f3f
int n,ans;
int c[25][25];
int vis[25];
void dfs(int i,int sum)//i是行号
{
if(sum>ans) //剪枝
return ;
if(i==n+1 && sum<ans)
{
ans=sum;
return ;
}
for(int j=1;j<=n;j++)
{
if(!vis[j])//遍历第i行 没有被遍历过列号j 的元素
{
vis[j]=1;
dfs(i+1,sum+c[i][j]);
vis[j]=0;
}
}
}
int main()
{
scanf("%d",&n);
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
scanf("%d",&c[i][j]);
ans=inf;
dfs(1,0);
printf("%d\n",ans);
return 0;
}
7-20 c++(g++)
#include<stdio.h>
#define MAX 100
#define max(x,y) ((x)>(y)?(x):(y))
int dp[MAX];
int ans = 0;
void solve(int a[],int n)
{
int i,j;
for(i=0;i<n;i++)
{
dp[i]=1;
for(j=0;j<i;j++)
{
if(a[i]>a[j])
dp[i]=max(dp[i],dp[j]+1);
}
}
ans=dp[0];
for(i=1;i<n;i++)
ans=max(ans,dp[i]);
}
int main()
{
int n;
scanf("%d",&n);
int a[n];
for(int i=0;i<n;i++)
scanf("%d",&a[i]);
solve(a,n);
printf("%d",ans);
return 0;
}
7-21 c++(g++)
#include<stdio.h>
#include"cstdio"
#include"iostream"
#include"string.h"
#include"algorithm"
using namespace std;
char str[1001];
int dp[1001][1001];
int main()
{
memset(dp,0,sizeof(dp));
char str1[1001];
scanf("%s",str);
int len=strlen(str);
int j=len-1;
for(int i=0;i<len;i++)
str1[j--]=str[i];
for(int i=1;i<=len;i++)
{
for(int j=1;j<=len;j++)
if(str[i-1]==str1[j-1])
dp[i][j]=max(dp[i][j],dp[i-1][j-1]+1);
else
dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
}
printf("%d\n",len-dp[len][len]);
}
7-22 c++(g++)
#include<bits/stdc++.h>
using namespace std;
long max3(long a,long b,long c)
{ if(a<b) a=b;
if(a>c) return a;
else return c;
}
long maxSubSum(int a[],int left,int right)
{ int i,j;
long maxLeftSum,maxRightSum;
long maxLeftBorderSum,leftBorderSum;
long maxRightBorderSum,rightBorderSum;
if(left==right)
{ if(a[left]>0)
return a[left];
else
return 0;
}
int mid=(left+right)/2;
maxLeftSum=maxSubSum(a,left,mid);
maxRightSum=maxSubSum(a,mid+1,right);
maxLeftBorderSum=0,leftBorderSum=0;
for(i=mid;i>=left;i--)
{ leftBorderSum+=a[i];
if(leftBorderSum>maxLeftBorderSum)
maxLeftBorderSum=leftBorderSum;
}
maxRightBorderSum=0,rightBorderSum=0;
for(j=mid+1;j<=right;j++)
{ rightBorderSum+=a[j];
if(rightBorderSum>maxRightBorderSum)
maxRightBorderSum=rightBorderSum;
}
return max3(maxLeftSum,maxRightSum,maxLeftBorderSum+maxRightBorderSum);
}
int main()
{ int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++)
{ cin>>a[i];
}
cout<<maxSubSum(a,0,n-1)<<endl;
}
7-23 c++(g++)
#include<bits/stdc++.h>
using namespace std;
int main() {
int n, k;
while (~scanf("%d,%d", &n, &k)) {
int dp[200][200];
int i, j;
for (i = 1; i <= n; i++) {
for (j = 1; j <= k; j++) {
if (j == 1 || i == 1)
dp[i][j] = 1;
else if (j == i) {
dp[i][j] = dp[i][j - 1] + 1;
}
else if (i < j) {
dp[i][j] = dp[i][i];
}
else if (i > j) {
dp[i][j] = dp[i][j - 1] + dp[i - j][j];
}
}
}
printf("%d\n", dp[n][k]);
}
return 0;
}
7-24 c++(g++)
#include<iostream>
using namespace std;
int f(int n)
{
int num1 = 1, num2 = 1, num3 = 0, i = 0;
if (n <= 1)
{
return num1;
}
for (i = 1; i < n; i++)
{
num3 = num1 + num2;
num1 = num2;
num2 = num3;
}
return num3;
}
int main()
{
int n,i;
cin>>n;
int a[n];
for(i=0;i<n;i++)
cin>>a[i];
for(i=0;i<n;i++)
cout<<f(a[i])<<endl;
return 0;
}
7-25 c++(g++)
#include<stdio.h>
int father[30001],num[30001],tmp,vis[30001],cnt[30001];
int Find(int x)
{
if(x != father[x])
father[x] = Find(father[x]);
return father[x];
}
int main(void)
{
int N,M,flag,fcur,ans=0;
scanf("%d%d",&N,&M);
for(int i=0;i<=N;i++)
father[i] = i;
for(int i = 1;i<=M;i++)
{
int cnt,lf;
scanf("%d",&cnt);
flag = 1;
for(int j=1;j<=cnt;j++){
int cur;
scanf("%d",&cur);
if(num[cur]==0){
if(j==1){
num[cur] = cur;
lf = father[cur];
}
num[cur] = cur;
father[cur] = lf;
}
else {
if(j==1)
lf = Find(cur);
int fcur = Find(cur);
father[fcur] = lf;
}
}
}
for(int i=1;i<=N;i++){
int fx = Find(i);
cnt[fx]++;
if(ans < cnt[fx])
ans = cnt[fx];
}
printf("%d\n",ans);
return 0;
}
7-26 c++(g++)
#include<iostream>
#include<cstring>
using namespace std;
typedef struct Node{
char sex;
int fId;
int mId;
}Node;
Node p[100001];
int flag,visited[100001];
void f(int a,int sum){
if(sum > 5 || a == -1 || a == 0)//如果代数大于5代,或者a==-1,说明都不在人世,
//或者a==0说明没有被赋值,直接返回
return;
visited[a]++;//记录被访问的次数
if(visited[a] >= 2)//如果五代以内的同一个人被访问超过2次,说明在五代之内有共同的祖先
flag = 0;
f(p[a].fId,sum + 1);//递归调用,a的父亲,代数+1
f(p[a].mId,sum + 1);//递归调用,a的母亲,代数+1
return;
}
int main(){
int n,selfId,fId,mId,k,a,b;
char c;
scanf("%d",&n);
for(int i = 0;i < n;i++){
scanf("%d %c%d%d",&selfId,&c,&fId,&mId);
p[selfId].sex = c;//记录自己的性别
p[selfId].fId = fId;//记录父亲的Id
p[selfId].mId = mId;
p[fId].sex = 'M';//记录自己父亲的性别,否则,可能会漏掉
p[mId].sex = 'F';//记录自己母亲的性别,否则,可能会漏掉
}
scanf("%d",&k);
while(k--){
flag = 1;//标记变量,默认为1
memset(visited,0,sizeof(visited));//每循环一次,必须进行一次初始化
scanf("%d%d",&a,&b);
if(p[a].sex == p[b].sex){
printf("Never Mind\n");
continue;
}
f(a,1);//以a为起点,代数为一代,进行寻找
f(b,1);//以a为起点,代数为一代,进行寻找
if(flag)
printf("Yes\n");
else
printf("No\n");
}
return 0;
}
7-27 c++(g++) ×
7-28 c++(g++)
#include<bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 5;
int d[MAXN];
vector<int>edge[MAXN];
void dfs(int x,int o)
{
d[x]=o;
for(int i=0;i<edge[x].size();i++)
dfs(edge[x][i],o+1);
}
int main()
{
int n,k,x,s;
cin>>n;
s=(n+1)*n/2;
for(int i=1;i<=n;i++)
{
cin>>k;
while(k--)
{
cin>>x;
s-=x;
edge[i].push_back(x);
}
}
dfs(s,1);
s=0;
for(int i=1;i<=n;i++)
if(d[s]<d[i])
s=i;
cout<<s<<endl;
return 0;
}
7-29 c++(g++)
#include <bits/stdc++.h>
using namespace std;
const int maxn=500+10;
const int INF=0x3f3f3f3f;
int V,E,s,t,num=0;
int cost[maxn][maxn];
int d[maxn];
int prev1[maxn];
int value[maxn];
int roadnum[maxn];
int amount[maxn];
bool used[maxn];
void dijkstra(int s)
{
memset(d,INF,sizeof(d));
memset(used,false,sizeof(used));
memset(prev1,-1,sizeof(prev1));
memset(roadnum,0,sizeof(roadnum));
memset(amount,0,sizeof(amount));
d[s]=0;
roadnum[s]=1;
amount[s]=value[s];
while(true)
{
int v=-1;
for(int u=0;u<V;u++)
{
if(!used[u]&&(v==-1||d[u]<d[v])) v=u;
}
if(v==-1) break;
used[v]=true;
for(int u=0;u<V;u++)
{
if(d[u]>d[v]+cost[v][u])
{
d[u]=d[v]+cost[v][u];
amount[u]=amount[v]+value[u];
roadnum[u]=roadnum[v];
prev1[u]=v;
//cout<<"gg1: "<<amount[u]<<" "<<u<<" "<<v<<endl;
}
else if(d[u]==d[v]+cost[v][u])
{
roadnum[u]+=roadnum[v];
if(amount[u]<amount[v]+value[u])
{
amount[u]=amount[v]+value[u];
prev1[u]=v;
//cout<<"gg2: "<<amount[u]<<" "<<u<<" "<<v<<endl;
}
}
}
}
}
int main()
{
scanf("%d %d %d %d",&V,&E,&s,&t);
for(int i=0;i<V;i++) memset(cost[i],INF,sizeof(cost[i]));
for(int i=0;i<V;i++) scanf("%d",&value[i]);
for(int i=0;i<E;i++)
{
int a,b,c; scanf("%d %d %d",&a,&b,&c);
cost[a][b]=cost[b][a]=c;
}
dijkstra(s);
int prevt[maxn];
int pos=0;
int tt=t;
for(;tt!=-1;tt=prev1[tt])
{
prevt[pos++]=tt;
}
printf("%d %d\n",roadnum[t],amount[t]);
for(int i=pos-1;i>=0;i--)
{
if(i) printf("%d ",prevt[i]);
else printf("%d",prevt[i]);
}
return 0;
}
7-30 c++(g++)
#include<iostream>
#include<cstring>
using namespace std;
int f[550],book[550];
struct edge{
int x,y;
};
edge edges[6000];
int n,m,sum;
int find(int x)
{
return f[x]<0?x:f[x]=find(f[x]);
}
void merge(int x,int y)
{
int rx=find(x);
int ry=find(y);
if(rx!=ry)
{
f[rx]+=f[ry];
f[ry]=rx;
}
}
int main()
{
cin>>n>>m;
memset(f,-1,sizeof(f));
for(int i=1;i<=m;i++)
{
int x,y;cin>>x>>y;
edges[i]=edge{x,y};
merge(x,y);
}
for(int i=0;i<n;i++)
{
if(f[i]<0)sum++;
}
int k;cin>>k;
for(int i=1;i<=k;i++)
{
int cnt=0;
memset(f,-1,sizeof(f));
int x;cin>>x;book[x]=1;
for(int j=1;j<=m;j++)
{
if(!book[edges[j].x]&&!book[edges[j].y])
{
merge(edges[j].x,edges[j].y);
}
}
for(int i=0;i<n;i++)
{
if(!book[i]&&f[i]<0)cnt++;
}
//sum=cnt;
if(cnt>sum) cout<<"Red Alert: City "<<x<<" is lost!"<<endl;
else cout<<"City "<<x<<" is lost."<<endl;
sum=cnt;
if(i==n)cout<<"Game Over."<<endl;
}
return 0;
}
7-31 c++(g++)
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF=0x3f3f3f3f;
const int maxn=1e3+10;
struct node
{
int x,y;
}a[maxn];
int n,d;
int di[maxn][maxn],via[maxn][maxn];
vector<int> apos;
stack<int> first;
void DFS(int i,int j)
{
if(via[i][j]==-1)
{
if(i!=0)
first.push(i);
}
else if(via[i][j]!=INF)
{
DFS(via[i][j],j);
DFS(i,via[i][j]);
}
return ;
}
int main()
{
scanf("%d %d",&n,&d);
if(d>=50)
{
printf("1");
return 0;
}
for(int i=1;i<=n;i++)
{
scanf("%d %d",&a[i].x,&a[i].y);
if(abs(a[i].x)+d>=50||abs(a[i].y)+d>=50)
{
apos.push_back(i);
}
}
a[0].x=a[0].y=0;
memset(di,INF,sizeof(di));
memset(via,INF,sizeof(via));
for(int i=0;i<=n;i++)
{
di[i][i]=0;
for(int j=i+1;j<=n;j++)
{
double x=0;
if(i==0) x=7.5;
double tx=a[i].x-a[j].x;
double ty=a[i].y-a[j].y;
double td=d+x;
if(tx*tx+ty*ty<=td*td)
{
di[i][j]=di[j][i]=1;
via[i][j]=via[j][i]=-1;
}
}
}
for(int k=0;k<=n;k++)
{
for(int i=0;i<=n;i++)
{
if(di[i][k]==INF) continue;
for(int j=0;j<=n;j++)
{
if(di[k][j]==INF) continue;
if(di[i][j]>di[i][k]+di[k][j])
{
di[i][j]=di[j][i]=di[i][k]+di[k][j];
via[i][j]=via[j][i]=k;
}
}
}
}
int ans=INF;
for(int i=0;i<apos.size();i++)
ans=min(ans,di[0][apos[i]]);
if(ans==INF)
{
printf("0");
return 0;
}
int pos=-1,dmin=INF;
for(int i=0;i<apos.size();i++)
{
if(ans==di[0][apos[i]])
{
DFS(0,apos[i]);
int t=first.top();
double tx=a[t].x;
double ty=a[t].y;
if(dmin>tx*tx+ty*ty)
{
pos=apos[i];
dmin=tx*tx+ty*ty;
}
while(!first.empty()) first.pop();
}
}
first.push(pos);
DFS(0,pos);
printf("%d\n",ans+1);
while(!first.empty())
{
int t=first.top(); first.pop();
printf("%d %d\n",a[t].x,a[t].y);
}
return 0;
}
7-32 c++(g++)
#include<iostream>
#include<vector>
#include<map>
using namespace std;
const int INF = 0x3f3f3f3f;
const int maxn = 200 + 10;
map<string,int> mp;
int n, k, w;
struct edge{
int to,cost;
};
vector <edge> G[maxn];
int num[maxn];
int dis[maxn];
int cnt[maxn];
int sumnum[maxn];
int pred[maxn];
int cntshort[maxn];
int book[maxn];
vector <int> ljd;
int s, des;
void dijsk()
{
for(int i = 0;i < n;i++)
dis[i] = INF;
dis[s] = 0;
cntshort[s] = 1;
book[s] = 1;
for(int i = 0;i < G[s].size();i++)
{
int next = G[s][i].to;
dis[next] = G[s][i].cost;
cntshort[next] = 1;
sumnum[next] = num[next];
pred[next] = s;
}
int min, minindex;
for(int i = 1;i <= n - 1;i++)
{
min = INF;
minindex = 0;
for(int i = 0;i < n;i++)
{
if(dis[i] < min && book[i] != 1)
{
min = dis[i];
minindex = i;
}
}
book[minindex] = 1;
for(int i = 0;i < G[minindex].size();i++)
{
edge& e = G[minindex][i];
int d2 = dis[minindex] + e.cost;
if(dis[e.to] > d2)
{
dis[e.to] = d2;
pred[e.to] = minindex;
cnt[e.to] = cnt[minindex] + 1;
sumnum[e.to] = sumnum[minindex] + num[e.to];
cntshort[e.to] = cntshort[minindex];
}
else if(dis[e.to] == d2)
{
cntshort[e.to] += cntshort[minindex];
if(cnt[e.to] < cnt[minindex] + 1)
{
pred[e.to] = minindex;
cnt[e.to] = cnt[minindex] + 1;
sumnum[e.to] = sumnum[minindex] + num[e.to];
}
else if(cnt[e.to] == cnt[minindex] + 1)
{
if(sumnum[e.to] < sumnum[minindex] + num[e.to])
{
sumnum[e.to] = sumnum[minindex] + num[e.to];
pred[e.to] = minindex;
}
}
}
}
}
}
void dfs(int *p, int x,vector <int>& a)
{
if(x == s)
{
a.push_back(x);
return ;
}
dfs(p, p[x], a);
a.push_back(x);
}
int main()
{
string city[maxn];
string city1, city2;
cin >> n >> k >> city1 >> city2;
city[0] = city1;
mp[city1] = 0;
for(int i = 1;i < n;i++)
{
cin >> city[i] >> w;
mp[city[i]] = i;
num[i] = w;
}
s = 0;
des = mp[city2];
int u, v;
for(int i = 0;i < k;i++)
{
cin >> city1 >> city2 >> w;
u = mp[city1]; v = mp[city2];
G[u].push_back((edge){v, w});
G[v].push_back((edge){u, w});
}
dijsk();
dfs(pred, des, ljd);
cout<<city[0];
for(int i = 1;i<ljd.size();++i){
cout<<"->"<<city[ljd[i]];
}
printf("\n%d %d %d",cntshort[des],dis[des],sumnum[des]);
return 0;
}
7-33 c++(g++)
#include <stdio.h>
#define MAXN 100
typedef struct
{
int arcs[MAXN][MAXN];
int vexnum,arcnum;
}AMGraph;
int main()
{
int n;
AMGraph G;
scanf("%d %d %d",&G.vexnum, &n, &G.arcnum );
int safecity[MAXN];
for(int i=0;i<n;i++)
{
scanf("%d",&safecity[i]);
}
for(int i=0;i<G.vexnum;i++)
{
for(int j=0;j<G.vexnum;j++)
{
G.arcs[i][j]=0;
}
}
for(int i=0;i<G.arcnum;i++)
{
int x,y;
scanf("%d %d",&x,&y);
G.arcs[x][y]=1;
G.arcs[y][x]=1;
}
int now,destination,flag=0;
scanf("%d %d",&now,&destination);
for(int i=0;i<n;i++)
{
if(destination==safecity[i])
{
flag=1;
break;
}
}
if(G.arcs[now][destination]==1)
{
if(flag)
printf("The city %d can arrive safely!\n",destination);
else
{
printf("The city %d is not safe!\n",destination);
}
}
else
{
if(flag)
printf("The city %d can not arrive safely!\n",destination);
else printf("The city %d is not safe!\n",destination);
}
return 0;
}
7-34 c++(g++)
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<queue>
#include<math.h>
using namespace std;
const int maxm = 105;
const int maxn = 5005;
const int INF = 1000009;
int flag[maxm][maxm], key[maxm*maxm], dis[maxn][maxm];
int id[maxm][maxm], vis[maxm*maxm], head[maxm*maxm], map[maxm][maxm];
int dx[4] = { 0,0,1,-1 };
int dy[4] = { 1,-1,0,0 };
struct node
{
int v, w, next;
}edge[maxm*maxm * 2];
struct point
{
int x, v;
point(int a, int b) :x(a), v(b) {}
point() {}
};
int n, m, s, t, cnt;
void init()
{
cnt = 0, s = 1, t = n*m;
memset(head, -1, sizeof(head));
memset(map, -1, sizeof(map));
memset(key, 0, sizeof(key));
}
void add(int u, int v, int w)
{
edge[cnt].v = v, edge[cnt].w = w;
edge[cnt].next = head[u], head[u] = cnt++;
}
int bfs()
{
queue<point>q;
memset(dis, 0x3f, sizeof(dis));
dis[1][s] = 0;
q.push(point(1, s));
while (!q.empty())
{
point now = q.front();q.pop();
int u = now.v;
dis[now.x | key[u]][u] = min(dis[now.x | key[u]][u], dis[now.x][u]);
now.x |= key[u];
for (int i = head[u];i != -1;i = edge[i].next)
{
int v = edge[i].v;
if ((now.x&edge[i].w) == edge[i].w)
{
if (dis[now.x][v] > dis[now.x][u] + 1)
{
dis[now.x][v] = dis[now.x][u] + 1;
q.push(point(now.x, v));
}
}
}
}
int ans = INF;
for (int i = 1;i < maxn;i++)
ans = min(ans, dis[i][t]);
if (ans == INF) return -1;
return ans;
}
int main()
{
int i, j, k, sum, p, len = 0;
int x1, x2, y1, y2, z, u, v;
scanf("%d%d%d%d", &n, &m, &p, &k);
init();
for (i = 1;i <= n;i++)
for (j = 1;j <= m;j++)
id[i][j] = ++len;
for (i = 1;i <= k;i++)
{
scanf("%d%d%d%d%d", &x1, &y1, &x2, &y2, &z);
u = id[x1][y1], v = id[x2][y2];
map[u][v] = map[v][u] = z;
if (z) add(u, v, 1 << z), add(v, u, 1 << z);
}
scanf("%d", &k);
for (i = 1;i <= k;i++)
{
scanf("%d%d%d", &x1, &y1, &z);
key[id[x1][y1]] |= 1 << z;
}
for (i = 1;i <= n;i++)
{
for (j = 1;j <= m;j++)
{
u = id[i][j];
for (k = 0;k < 4;k++)
{
int x = i + dx[k];
int y = j + dy[k];
v = id[x][y];
if (map[u][v] == -1 && id[x][y])
add(u, v, 1);
}
}
}
printf("%d\n", bfs());
return 0;
}
7-35 c++(g++) ×
7-36 c++(g++) ×
7-37 c++(g++)
#include <stdio.h>
#include <string.h>
int main()
{
char str[20][10],t[20],str1[10];
int i,j,n=0;
while(1)
{
scanf("%s",str1);
if(str1[0]=='#')
{
break;
}
else
{
strcpy(str[n],str1);
n++;
}
}
for(i=0;i<n-1;i++)
for(j=0;j<n-i-1;j++)
{
if(strlen(str[j])>strlen(str[j+1]))
{
strcpy(t,str[j]);
strcpy(str[j],str[j+1]);
strcpy(str[j+1],t);
}
}
for(i=0;i<n;i++)
{
printf("%s ",str[i]);
}
return 0;
}
7-38 c++(g++)
#include<iostream>
#include<algorithm>
#include<cstring>
#include<climits>
using namespace std;
bool cmp(double a,double b){
return a > b;
}
int main(){
int n,k,m,a,mx,mn,kx;
double sum,arr[10001];
scanf("%d%d%d",&n,&k,&m);
memset(arr,0,sizeof(arr));
kx = 0;
for(int i = 0;i < n;i++){
mx = INT_MIN,mn = INT_MAX,sum = 0;
for(int d = 0;d < k;d++){
scanf("%d",&a);
mx = max(a,mx);
mn = min(a,mn);
sum += a;
}
sum = sum - mx - mn;
arr[kx++] = sum / (k - 2);
}
sort(arr,arr + kx,cmp);
for(int i = m - 1;i >= 0;i--){
if(i)
printf("%.3lf ",arr[i]);
else
printf("%.3lf\n",arr[i]);
}
return 0;
}
7-39 c++(g++)
#include <iostream>
using namespace std;
int main()
{
int n,i,j,k,p;
int a[100][100];
cin>>n;
for(i=1;i<=n;i++)
{
a[i][i]=0;
}
for(i=1;i<=n;i++)
{
for(j=i+1;j<=n;j++)
{
cin>>a[i][j];
}
}
for(i=2;i<=n;i++)
{
for(j=i+1;j<=n;j++)
{
k=j-i;
for(p=k;p<j;p++)
{
if(a[k][j]>a[k][p]+a[p][j])
a[k][j]=a[k][p]+a[p][j];
}
}
}
cout<<a[1][n]<<endl;
return 0;
}
7-40 c++(g++)
#include<iostream>
#include<queue>
using namespace std;
int main()
{
int n,m;
priority_queue< int, vector<int>, greater<int> > q;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>m;
q.push(m);
}
int sum =0;
while(!q.empty())
{
int x = q.top();
q.pop();
if(q.empty())
break;
int y = q.top();
q.pop();
x+=y;
sum+=x;
q.push(x);
}
cout<<sum<<endl;
return 0;
}