Educational Codeforces Round 93 (Rated for Div. 2)

C

#include<bits/stdc++.h>
using namespace std;
long long t,n,i,cnt,ans;string str;map<int,int>mp;
int main(){
	for(cin>>t; t-- and cin>>n>>str; cout<<ans<<'\n')
        for(mp.clear(),mp[0]=1,cnt=ans=i=0; i<n; ans += mp[cnt+=str[i++]-49]++);
        //mp[]裡的下標cnt算出來的就是當前位置與之前位置的整個區間的和值與區間長度的差
}

D

#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
#include <map>
using namespace std;
 
typedef long long ll;
const int maxn = 205;
 
int R[maxn],G[maxn],B[maxn];
ll dp[maxn][maxn][maxn];
 
int main() {
    
    int n1,n2,n3;scanf("%d%d%d",&n1,&n2,&n3);
    for(int i = 1;i <= n1;i++) {
        scanf("%d",&R[i]);
    }
    for(int i = 1;i <= n2;i++) {
        scanf("%d",&G[i]);
    }
    for(int i = 1;i <= n3;i++) {
        scanf("%d",&B[i]);
    }
    sort(R + 1,R + 1 + n1);
    sort(G + 1,G + 1 + n2);
    sort(B + 1,B + 1 + n3);
    
    for(int i = 0;i <= n1;i++) {
        for(int j = 0;j <= n2;j++) {
            for(int k = 0;k <= n3;k++) {
                dp[i + 1][j + 1][k] = max(dp[i + 1][j + 1][k],dp[i][j][k] + R[i + 1] * G[j + 1]);
                dp[i + 1][j][k + 1] = max(dp[i + 1][j][k + 1],dp[i][j][k] + R[i + 1] * B[k + 1]);
                dp[i][j + 1][k + 1] = max(dp[i][j + 1][k + 1],dp[i][j][k] + G[j + 1] * B[k + 1]);
            }
        }
    }
    
    printf("%lld\n",dp[n1][n2][n3]);
    
    return 0;
}