Longest Common subSequence

#include <bits/stdc++.h>

int max(int a, int b);

int lcs(char* X, char* Y, int m, int n)
{
	int L[m + 1][n + 1];
	int i, j;
  
	that L[i][j] contains length of LCS of X[0..i-1] and Y[0..j-1] */
	for (i = 0; i <= m; i++) {
		for (j = 0; j <= n; j++) {
			if (i == 0 || j == 0)
				L[i][j] = 0;

			else if (X[i - 1] == Y[j - 1])
				L[i][j] = L[i - 1][j - 1] + 1;

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

	return L[m][n];
}

int max(int a, int b)
{
	return (a > b) ? a : b;
}

int main()
{
	char X[] = "AGGTAB";
	char Y[] = "GXTXAYB";

	int m = strlen(X);
	int n = strlen(Y);

	printf("Length of LCS is %d\n", lcs(X, Y, m, n));

	return 0;
}