很好的一道思维题目（有坑点的）

Counting SubsequencesTime Limit: 5000 MSMemory Limit: 65536 KTotal Submit: 850(264 users)Total Accepted: 240(208 users)Rating: Special Judge: NoDescription

 "47 is the quintessential random number," states the 47 society. And there might be a grain of truth in that.

For example, the first ten digits of the Euler's constant are:

2 7 1 8 2 8 1 8 2 8

And what's their sum? Of course, it is 47.

You are given a sequence S of integers we saw somewhere in the nature. Your task will be to compute how strongly does this sequence support the above claims.

We will call a continuous subsequence of S interesting if the sum of its terms is equal to 47.

E.g., consider the sequence S = (24, 17, 23, 24, 5, 47). Here we have two interesting continuous subsequences: the sequence (23, 24) and the sequence (47).

Given a sequence S, find the count of its interesting subsequences.

Input

The first line of the input file contains an integer T(T <= 10) specifying the number of test cases. Each test case is preceded by a blank line.

The first line of each test case contains the length of a sequence N(N <= 500000). The second line contains N space-separated integers – the elements of the sequence. Sum of any continuous subsequences will fit in 32 bit signed integers.

Output

For each test case output a single line containing a single integer – the count of interesting subsequences of the given sentence.

Sample Input

2

 

13
2 7 1 8 2 8 1 8 2 8 4 5 9

 

7
2 47 10047 47 1047 47 47

Sample Output3
4ac代码：

#include<bits/stdc++.h>using namespace std;map<long long  ,int >w;int main(){    int t;    scanf("%d",&t);    while(t--)    {        int n;        w.clear();        scanf("%d",&n);        long long  sum=0,ans=0;        w[sum]=1;        for(int i=0; i<n; i++)        {            long long  q;            scanf("%lld",&q);            sum+=q;            w[sum]++;                ans+= w[sum-47];        }        printf("%lld\n",ans);    }}

这个题比较坑人的一点就是自然数是包括0的。