Find subarray with given sum

问题：Given an unsorted array of integers, find a continous subarray which adds to a given number.

注意：数组中有正有负。

参见：http://stackoverflow.com/questions/5534063/zero-sum-subarray

#include<cstdio>
#include<map>
#include<string.h>
using namespace std;

bool findsub(int A[], int n, int target, int &left, int &right)
{
if(n == 0)
return false;

multimap<int, int> sum;
int *tmp = new int[n+1]; //tmp[i] 表示前i项之和
tmp[0] = 0;
for(int i=1;i<=n;i++)
{
tmp[i] = tmp[i-1] + A[i-1];
sum.insert(pair<int,int>(tmp[i], i));
}

int i;
for(i=0;i<=n;i++)
{
multimap<int, int>::iterator it = sum.find(tmp[i] + target);
if(it == sum.end())
continue;
for(;(*it).first == tmp[i] + target;it++)
{
right = (*it).second;
if(right <= i)
continue;
left = i+1;
return true;
}
}
return false;
}

int main()
{
int A[10002];
int n, target;
int left, right;
while(scanf("%d",&n)!=EOF)
{
for(int i=0;i<n;i++)
scanf("%d", &A[i]);
scanf("%d",&target);
if(findsub(A, n, target, left, right))
printf("%d %d\n",left, right);
else
printf("No\n");
}
return 1;
}