https://www.nowcoder.com/acm/contest/144#question
凉了啊，四题最后一名
D：水题
solved by lyy
#include <bits/stdc++.h>
using namespace std;
#define ll long long
int t,n,m,k;
int v[100005];
int main()
{
scanf("%d",&t);
int step=0;
while (t--)
{
step++;
memset(v,0,sizeof(v));
scanf("%d%d%d",&n,&m,&k);
while (k--)
{
int a,b,c;
scanf("%d%d%d",&a,&b,&c);
v[b]=max(v[b],c);
}
ll ans=0;
for (int i=1;i<=m;i++)
{
ans+=v[i];
}
printf("Case #%d: %lld\n",step,ans);
}
return 0;
}A：
solved by wyq
#include <bits/stdc++.h>
using namespace std;
#define ll long long
queue<int> q;
int a[20005][20];
int main()
{
int T,i,x,y,n,len,max1,max2,j,count=0;
scanf("%d",&T);
memset(a,-1,sizeof(a));
while(T--)
{
count++;
scanf("%d",&n);
len=1<<n;
for(i=1;i<=len;i++)
{
for(j=1;j<=n;j++)
scanf("%d",&a[i][j]);
}
for(i=1;i<=len;i++)
{
sort(a[i]+1,a[i]+n+1);
q.push(i);
}
while(true)
{
//printf("%d\n",q.size());
if(q.size()==1)break;
x=q.front();q.pop();
y=q.front();q.pop();
//printf("%d %d\n",x,y);
max1=0;
for(i=n;i>=1;i--)
{
if(a[x][i]==-1)continue;
if(a[x][i]>max1)max1=a[x][i];
}
max2=0;
for(i=n;i>=1;i--)
{
if(a[y][i]==-1)continue;
if(a[y][i]>max2)max2=a[y][i];
}
if(max1>max2)
{
//printf("%dwin\n",x);
q.push(x);
for(i=1;i<=n;i++)
{
if(a[x][i]==-1)continue;
if(a[x][i]>max2)
{
a[x][i]=-1;
break;
}
}
}
else
{
//printf("%dwin\n",y);
q.push(y);
for(i=1;i<=n;i++)
{
if(a[y][i]==-1)continue;
if(a[y][i]>max1)
{
a[y][i]=-1;
break;
}
}
}
}
printf("Case #%d: %d\n",count,q.front());
q.pop();
}
return 0;
}J：瞎搞过的，发现题解说的很有道理啊，结论知道，但是当时没想到，方法也跟这个差不多吧
solved by lyy
#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int maxx = 1e7+2;
vector<unsigned int> v;
int main()
{
int n,T;
scanf("%d",&T);
int cnt=0;
while(T--)
{
v.clear();
int a,b,c;
scanf("%d%u%u%u",&n,&a,&b,&c);
unsigned int x = a,y = b,z = c;
for(int i = 0; i < n; i++)
{
unsigned int t;
x ^= x << 16;
x ^= x >> 5;
x ^= x << 1;
t = x;
x = y;
y = z;
z = t ^ x ^ y;
v.push_back(z);
}
//sort(v.begin(),v.end());
unsigned long long nowmax=0,now;
if (v.size()<=1000000)
{
for (int i=0;i<min(2,n);i++)
{
for (int j=i+1;j<n;j++)
{
if (v[i]<v[j]) swap(v[i],v[j]);
}
}
for(int i=0;i<n;i++)
{
if(v[i]<nowmax/v[i]) continue;
for(int j=0;j<n;j++)
{
if(v[j]<nowmax/v[i] || i==j) continue;
now=(unsigned long long)v[i]*v[j]/(unsigned long long)__gcd(v[i],v[j]);
nowmax=max(now,nowmax);
}
}
}
else
{
while (v.size()>1000000)
{
vector<unsigned int> vv;
unsigned int r=max(v[100],v[200]);
for (auto x:v)
{
if (x>r) vv.push_back(x);
}
v=vv;
//cout<<v.size()<<endl;
}
for (int i=0;i<min(2,(int)v.size());i++)
{
for (int j=i+1;j<v.size();j++)
{
if (v[i]<v[j]) swap(v[i],v[j]);
}
}
for(int i=0;i<v.size();i++)
{
if(v[i]<nowmax/v[i]) continue;
for(int j=0;j<v.size();j++)
{
if(v[j]<nowmax/v[i] || i==j) continue;
now=(unsigned long long)v[i]*v[j]/(unsigned long long)__gcd(v[i],v[j]);
nowmax=max(now,nowmax);
}
}
}
printf("Case #%d: %llu\n",++cnt,(unsigned long long)nowmax);
}
return 0;
}C：就是推推公式，没有预先处理逆元会TLE（我就是这样T的）
solved by lyy
#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll mod=998244353;
ll n,m;
int t;
long long inv(long long a,long long m)
{
if(a == 1)return 1;
return inv(m%a,m)*(m-m/a)%m;
}
ll f[1000005];
int main()
{
for (int i=1;i<=1000000;i++)
{
f[i]=inv(i,mod);
}
cin>>t;
int step=0;
while (t--)
{
step++;
cin>>n>>m;
// if (m==1)
// {
// printf("Case #%d: %lld\n",step,1);
// continue;
// }
int p=(int)min(n,m);
ll x=1;
ll y=m%mod;
ll ans=0;
for (int i=1;i<=p;i++)
{
//cout<<x<<' '<<y<<endl;
ans=(ans+x*y)%mod;
if (i!=p)
{
y=y*((m-i)%mod)%mod;
x=x*((n-i)%mod)%mod*f[i]%mod;
}
}
printf("Case #%d: %lld\n",step,ans);
}
return 0;
}