Dynamic programming longest repeating subsequence

Author: CodeRex7

geekforgeeks/DP/a.out

@@ -0,0 +1,43 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+string longestRepeat(string a)
+{
+	int n=a.size();
+	vector< vector<int> >dp(n+1);
+	for(int i=0;i<n+1;i++){
+		dp[i].resize(n+1);
+			}
+	for(int i=1;i<n+1;i++){
+		for(int j=1;j<n+1;j++){
+			if(a[i-1]==a[j-1] && i!=j)
+				dp[i][j]=1+dp[i-1][j-1];
+			else
+				dp[i][j]=max(dp[i][j-1],dp[i-1][j]);	
+			}
+		}
+	string rev="";
+	int i=n,j=n;
+	while(i>0 && j>0){
+		if(dp[i][j]==1+dp[i-1][j-1])
+		{
+			rev+=a[i-1];
+			i--;
+			j--;
+		}
+		else if(dp[i][j]==dp[i-1][j-1])
+			i--;
+		else
+			j--;
+	}
+	reverse(rev.begin(),rev.end());
+	return rev;
+}
+
+int main()
+{
+	string a;
+	cin>>a;
+	cout<<longestRepeat(a)<<endl;
+	return 0;
+}