GFG PTOD | 02 Jan 2025 | Subarrays with sum K

int countSubarrays(vector<int> &arr, int k) {
        // code here
        unordered_map<int, int> map;
        int count = 0, sum = 0;
        
        for(int i=0; i<arr.size(); i++) {
            sum+= arr[i];
            if(sum==k) count++;
            if(map.find(sum-k) != map.end()) count+=map[sum-k];
            map[sum]++;
        }
        return count;
    }