Create Shortest Subarray with Sum at least K.cpp

Author: Sinha199

Diff for: Shortest Subarray with Sum at least K.cpp

@@ -0,0 +1,57 @@
+/* 
+   Return the length of the shortest, non-empty, contiguous subarray of A with sum at least K.
+   If there is no non-empty subarray with sum at least K, return -1.
+    
+   Input: A = [2,-1,2], K = 3
+   Output: 3
+
+*/
+
+
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int shortestSubarray(vector<int>& A, int K) 
+{
+        priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>pq;   // min heap to store the length and sum of the subarray
+        int sum = 0;
+        int ans = INT_MAX;
+        for(int i=0;i<A.size();i++){
+            sum += A[i];
+            if(sum >= K){
+                ans = min(ans,i+1);
+            }
+            while(pq.size() >0 && sum-pq.top().first >=K ){
+                ans = min(ans,i-pq.top().second);
+                pq.pop();
+            }
+            pq.push({sum,i});
+        }
+        return ans == INT_MAX ? -1 : ans;
+}
+
+int main()
+{
+      int K;
+      cin >> K;
+      cout << "Enter the number of elements in the array" ; 
+      int n;
+      cin >> n;
+      vector<int> arr(n);
+      for(int i=0;i<n;i++)
+      {
+          int x;
+          cin >> x;
+          arr.push_back(x);
+      }
+      
+      cout << shortestSubarray(arr , K);
+      
+      return 0;
+}
+
+
+
+
+