Added solution - LeetHub

Author: ayushnagar123

The Celebrity Problem - GFG/the-celebrity-problem.cpp

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+// { Driver Code Starts
+//Initial template for C++
+
+#include<bits/stdc++.h>
+using namespace std;
+
+ // } Driver Code Ends
+//User function template for C++
+
+class Solution 
+{
+    public:
+    //Function to find if there is a celebrity in the party or not.
+    int celebrity(vector<vector<int> >& arr, int people) 
+    {
+        // code here 
+        stack<int> s;
+        for(int i=0;i<people;i++){
+            s.push(i);
+        }
+        while(s.size()>1){
+            int p1 = s.top();
+            s.pop();
+            int p2 = s.top();
+            s.pop();
+            if(arr[p1][p2]==1 && arr[p2][p1]==0){
+                s.push(p2);
+            }
+            else if(arr[p1][p2]==0 && arr[p2][p1]==1){
+                s.push(p1);
+            }
+        }
+        if(s.empty()){
+            return -1;
+        }
+        int expected = s.top();
+        for(int i=0;i<people;i++){
+            if(i!=expected && (arr[expected][i]!=0 || arr[i][expected]!=1)){
+                return -1;
+            }
+        }
+        return expected;
+    }
+};
+
+// { Driver Code Starts.
+
+int main()
+{
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        int n;
+        cin>>n;
+        vector<vector<int> > M( n , vector<int> (n, 0));
+        for(int i=0;i<n;i++)
+        {
+            for(int j=0;j<n;j++)
+            {
+                cin>>M[i][j];
+            }
+        }
+        Solution ob;
+        cout<<ob.celebrity(M,n)<<endl;
+
+    }
+}
+  // } Driver Code Ends