Longest Common Sub-Sequence

#include<bits/stdc++.h>

using namespace std;

int lcs(string s1, string s2, int n, int m)

{

    int L[n+1][m+1];

    int i, j;

    for(i=0;i<=n;i++)

    {

        for(j=0;j<=m;j++)

        {

            if(i == 0 || j == 0)

                L[i][j] = 0;

            else if(s1[i-1] == s2[j-1])

                L[i][j] = 1 + L[i-1][j-1];

            else

                L[i][j] = max(L[i-1][j], L[i][j-1]);

        }

    }

    return L[n][m];

}

int main()

{

    string s1, s2;

    cout << "Enter First String :: ";

    cin >> s1;

    cout << "Enter Second String :: ";

    cin >> s2;

    int n = s1.size();

    int m = s2.size();

    cout << endl << "Longest Common Sub-Sequence Size is :: ";

    cout << lcs(s1, s2, n, m) << endl;

    return 0;

}