Add files via upload (#252)

Author: parthsaini08

Leetcode 930 solution.cpp

@@ -0,0 +1,16 @@
+class Solution {
+public:
+    int numSubarraysWithSum(vector<int>& nums, int goal) {
+        unordered_map<int,int> m;
+        m[0]=1;
+        int ans=0,s=0;
+        for(auto x:nums)
+        {
+            s+=x;
+            if(m.find(s-goal)!=m.end())
+                ans+=m[s-goal];
+            m[s]++;
+        }
+        return ans;
+    }
+};