560.cpp

class Solution {
public:
    int subarraySum(vector<int>& nums, int k) {
        int sum=0;
        int count=0;
        map<int,int>mp;
        mp[0]=1;
        for(int i=0;i<nums.size();i++){
            sum=sum+nums[i];
            if(mp.find(sum-k)!=mp.end()){
                count=count+mp[sum-k];
            }
             mp[sum]++;        
            }
        return count;
    }
};