codeforces:ProblemMset

最近一个月在codeforces上做的题(做个记录)

后面太多了就不把代码一一放出了，只放置了链接，可根据链接找到提交的代码.

最小子矩阵

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <cstring>

using namespace std;

const int N = 1e2+7;
int a[N],b[N];
int w[N][N];
int dp[N];
int n,m,x,y;

double maxSub(int c[]){
    
    
    int b = 0;
    int cnt = 0;
    double avg = 0.0,s = 0.0;
    
    for(int i=0;i<m;i++){
    
    
        if(b<0){
    
    
            b = c[i];
            cnt = 0;
        }else{
    
    
            b += c[i];
            cnt++;
            avg = b/(cnt*1.0);
        }
        
        if(cnt>=x){
    
    
            s = max(s,avg);
        }
    }
    
    return s;
}

int main()
{
    
    
    scanf("%d%d%d%d",&n,&m,&x,&y);
    for(int i=0;i<n;i++)
        scanf("%d",&a[i]);
    for(int i=0;i<m;i++)
        scanf("%d",&b[i]);
    
    for(int i=0;i<n;i++)
        for(int j=0;j<m;j++)
            w[i][j] = a[i] + b[j];
    
    double maxavg = 0.0;
    int f = 0;
    for(int i=0;i<n;i++){
    
    
        memset(dp,0,sizeof(dp));
        f = 0;
        
        for(int j=i;j<n;j++){
    
    
            f++;
            for(int k=0;k<m;k++){
    
    
                dp[k] += w[j][k];
            }
            if(f>=y){
    
    
                maxavg = max(maxavg,maxSub(dp));
            }
        }
    }
    
    printf("%.10lf\n",maxavg);
    
    return 0;
}

1504A - Déjà Vu:构造.
1513B AND Sequences(数学+位运算.)
构造

#include <iostream>
#include <cstdio>

using namespace std;

typedef long long ll;

int main()
{
    
    
	ll a,b;
	ll t;	
	scanf("%lld",&t);
	getchar();
	while(t--){
    
    
		scanf("%lld%lld",&a,&b);
		
		if(b==1){
    
    
			puts("NO");
		}else{
    
    
			puts("YES");
			printf("%lld %lld %lld\n",a,2*a*b-a,2*a*b);
		}
	}
	
	return 0;
}

构造，数学

	while(t--){
    
    
		cin >> n;
		for(int i=0;i<n;i++)
			scanf("%d",&a[i]);
			
		cout << n/2 << endl;
		
		for(int i=0;i<n-1;i+=2){
    
    
			cout << i+1 << " " << i+2 << " " << min(a[i],a[i+1]) << " " << k << endl;
		}
	}

数学

	int t,k;
	cin >> t;
	while(t--){
    
    
		cin >> k;
		
		int g = gcd(k,100-k);
//		cout << g << endl;
		cout << k/g + (100-k)/g << endl;
	}

贪心

void solve(){
    
    
	
	bool flag = false;
	cin >> n;
	for(int i=0;i<n;i++){
    
    
		cin >> a[i];
		if(a[i]!=i+1){
    
    
			flag = true;
		}
	}
	
	if(!flag){
    
    
		cout << "0" << endl;
		return;
	}
	
	if(a[0]==n&&a[n-1]==1){
    
    
		cout << "3" << endl;
	}else if(a[0]==1||a[n-1]==n){
    
    
		cout << "1" << endl;
	}else{
    
    
		cout << "2" << endl;
	}
	return;
}

A.Mean Inequality

	while(t--){
    
    
		cin >> n;
		
		for(int i=0;i<2*n;i++)
			scanf("%d",&a[i]);
			
		sort(a,a+2*n);
		
		for(int i=0,j=n;i<n;i++,j++){
    
    
			printf("%d %d",a[i],a[j]);
			
			if(i!=n-1){
    
    
				printf(" ");
			}
		}
		printf("\n");
	}

B. I Hate 1111

	while(t--){
    
    
		cin >> a;
		
		if(a/111>=a%11)
			puts("YES");
		else
			puts("NO");
	}

C1. Potions (Easy Version)

#include <iostream>
#include <cstdio>
#include <queue>

using namespace std;

typedef long long ll;

int main()
{
    
    
    int n;
    scanf("%d",&n);
    
    ll sum = 0;
    int x;
    int ans = 0;
    priority_queue<int,vector<int>,greater<int> > pq;
    while(n--){
    
    
        scanf("%d",&x);
        sum += x;
        ans++;
        pq.push(x);
        
        if(sum<0){
    
    
            sum -= pq.top();
            pq.pop();
            ans--;
        }
    }
    printf("%d\n",ans);
    return 0;
}

C2. Potions (Hard Version)

同上.

B. Histogram Ugliness

//割去突出部分即可

#include <iostream>
#include <cstdio>
#include <algorithm>

using namespace std;

long long a[500010];

int main()
{
    
    
	int t,n;
	scanf("%d",&t);
	while(t--){
    
    
		long long ans = 0;
		
		scanf("%d",&n);
		
		for(int i=0;i<n;i++)
			scanf("%d",&a[i]);
			
		for(int i=1;i<n-1;i++){
    
    
			if(a[i]>a[i-1]&&a[i]>a[i+1]){
    
    
				ans += min(a[i]-a[i-1],a[i]-a[i+1]);
				a[i] = a[i+1]>a[i-1]?a[i+1]:a[i-1];
			}
		}
		
		if(a[0]>a[1]){
    
    
			ans += a[0]-a[1];
			a[0] = a[1];
		}
		
		
		if(a[n-1]>a[n-2]){
    
    
			ans += a[n-1]-a[n-2];
			a[n-1] = a[n-2];
		}
		
		for(int i=1;i<n;i++){
    
    
			ans += abs(a[i]-a[i-1]);
		}
		
		cout << (ans+a[0]+a[n-1]) << endl;
	}
	
	
	return 0;
}

A. Arithmetic Array

#include <iostream>
#include <cstdio>

using namespace std;

int main()
{
    
    
	int t;
	scanf("%d",&t);
	while(t--){
    
    
		int n;
		scanf("%d",&n);
		
		int sum = 0,a;
		for(int i=0;i<n;i++){
    
    
			scanf("%d",&a);
//			cnt ++;
			sum += a;
		}
		int ans = sum - n;
		
		if(ans < 0){
    
    
			puts("1");
		}else{
    
    
			printf("%d\n",ans);
		}
	}
	
	
	return 0;
 }