LC Subsequence

#include<bits/stdc++.h>
#define MAX 1000
using namespace std;

int m, n;
int c[MAX][MAX], b[MAX][MAX];

int LCSlength(string x, string y){
        int m, n;
        m = x.size();
        n = y.size();

        for(int i=1; i<=m; i++) c[i][0] = 0;
        for(int i=0; i<=n; i++) c[0][i] = 0;

        for(int i=1; i<=m; i++){
                for(int j=1; j<=n; j++){
                        if(x[i-1] == y[j-1]){
                                c[i][j] = c[i-1][j-1] + 1;
                                b[i][j] = 1;
                        }
                        else if(c[i-1][j] >= c[i][j-1]){
                                c[i][j] = c[i-1][j];
                                b[i][j] = 2; //from north
                        }
                        else{
                                c[i][j] = c[i][j-1];
                                b[i][j] = 3;//from west
                        }
                }
        }

        return c[m][n];
}