HDU Tokitsukaze and Multiple 题解（贪心）

题目链接

题目思路

emm其实就是要明白右端点往左贪心就好了（白书上有介绍）

代码

#include<set>
#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<vector>
#include<string>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<unordered_map>
#define fi first
#define se second
#define debug printf(" I am here\n");
using namespace std;
typedef unsigned long long ull;
typedef pair<int,int > pii;
const int maxn=1e5+5,inf=0x3f3f3f3f;
const double eps=1e-10;
int t,n,p,a[maxn],pre[maxn],re[maxn];
pii st[maxn];
signed main(){
    scanf("%d",&t);
    while(t--){
        scanf("%d%d",&n,&p);
        for(int i=1;i<=n;i++){
            scanf("%d",&a[i]);
            pre[i]=(pre[i-1]+a[i])%p;
        }
        int ans=0;
        map<int,int> mp;
        mp.clear();
        mp[0]=1;
        for(int i=1;i<=n;i++){
            if(mp.count(pre[i])){
                ans++;
                mp.clear();
            }
            mp[pre[i]]=1;
        }
        printf("%d\n",ans);
    }
    return 0;
}