LCS

 #include <stdio.h> #include<string.h> char X[100]="_",Y[100]="_"; int dp[100][100]; int max(int x,int y) { return (x>y)?x:y; } int lcs(int m,int n) { int i, j; for (i = 0; i <= n; i++) dp[i][0]=0; for (j = 0; j <= m; j++) dp[0][j]=0; for ( i = 1; i <= n; i++) { for ( j = 1; j <= m; j++) { if (Y[i]==X[j]) { dp[i][j]=dp[i-1][j-1]+1; } else dp[i][j]=max(dp[i-1][j],dp[i][j-1]); } } return dp[n][m]; } int main() { char s1[]="abcdaf"; char s2[]="acbcf"; int m,n; m=strlen(s1); n=strlen(s2); strcat(X,s1); strcat(Y,s2); int l=lcs(m,n); printf("%d",l); }