Create largest_subarray_with_zero_sum.cpp

Program to find longest subarray with zero sum in an array of positive and negative integers.

Author: cvivek503

Diff for: largest_subarray_with_zero_sum.cpp

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+/* Program to find longest subarray with zero sum in an array of positive and negative integers /*
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int maxLen(int A[], int n);
+
+int main()
+{
+    int T;
+    cin >> T;
+    while (T--)
+    {
+        int N;
+        cin >> N;
+        int A[N];
+        for (int i = 0; i < N; i++)
+            cin >> A[i];
+        cout << maxLen(A, N) << endl;
+    }
+}
+
+
+
+int maxLen(int A[], int n)
+{   unordered_map<int,int> a;
+int s=0,m=0;
+a[0]=-1;
+    for(int i=0;i<n;++i)
+    {
+        s+=A[i];
+        auto y=a.find(s);
+        if(y==a.end())
+        a[s]=i;
+        else
+        {
+            if(i-a[s]>m)
+            m=i-a[s];
+            
+        }
+        
+        
+    }
+    return m;
+}