Longest Common Subsequence.cpp

int longestCommonSubsequence(string a, string b) {
        int m   = a.length();
        int n = b.length();
        int t[m+1][n+1];
        //initialisation
        for(int i=0;i<(n+1);i++)t[0][i]=0;
        for(int i=0;i<(m+1);i++)t[i][0]=0;
        //code variations
        for(int i=1;i<(m+1);i++){
            for(int j=1;j<(n+1);j++){
                if(a[i-1]==b[j-1]){
                    t[i][j] = 1+ t[i-1][j-1];
                }else{
                    t[i][j] = max(t[i-1][j], t[i][j-1]);
                }
            }
        }
        return t[m][n];
    }


//Input: text1 = "abcde", text2 = "ace" 
//Output: 3  
//Explanation: The longest common subsequence is "ace" and its length is 3.