Problem C: Longest Common Subsequence

Sequence 1:

Sequence 2:


Given two sequences of characters, print the length of the longest common subsequence of both sequences. For example, the longest common subsequence of the following two sequences:

abcdgh
aedfhr

Input consists of pairs of lines. The first line of a pair contains the first string and the second line contains the second string. Each string is on a separate line and consists of at most 1,000 characters

For each subsequent pair of input lines, output a line containing one integer number which satisfies the criteria stated above.

Sample input

a1b2c3d4e
zz1yy2xx3ww4vv
abcdgh
aedfhr
abcdefghijklmnopqrstuvwxyz
a0b0c0d0e0f0g0h0i0j0k0l0m0n0o0p0q0r0s0t0u0v0w0x0y0z0
abcdefghijklmnzyxwvutsrqpo
opqrstuvwxyzabcdefghijklmn

Output for the sample input

4
3
26
14

 
#include <stdio.h>
#include <string.h>
char A[1001], B[1001];
short LCS[1001][1001];
int main() {
	int i, j;
	while(gets(A)) {
		gets(B);
		memset(LCS, 0, sizeof(LCS));
		int la = strlen(A), lb = strlen(B);
		for(i = 1; i <= la; i++) {
			for(j = 1; j <= lb; j++) {
				if(A[i-1] == B[j-1])
					LCS[i][j] = LCS[i-1][j-1]+1;
				else
					LCS[i][j] = LCS[i][j-1] > LCS[i-1][j] ?	LCS[i][j-1] : LCS[i-1][j];
			}
		}
		printf("%d\n", LCS[la][lb]);
	}
    return 0;
}