/**
knakul853
**/
class Solution {
public:
    int subarraySum(vector<int>& nums, int k) {

        int cur = 0;
        int n = (int)nums.size();
        unordered_map<int, int>ump;
        int ans = 0;
        ump[0] = 1;
        for( int i=0;i<n;i++ )
        {
            cur+=nums[i];
            if(ump.count(cur - k))ans+=ump[cur-k];

            ump[cur]++;
        }

        return ans;
    }
};