Common Subsequence(poj1458)

Common Subsequence

Time Limit: 1000MS		Memory Limit: 10000K
Total Submissions: 36432		Accepted: 14536

DescriptionA subsequence of a given sequence is the given sequence with some elements (possible none) left out. Given a sequence X = < x1, x2, ..., xm > another sequence Z = < z1, z2, ..., zk > is a subsequence of X if there exists a strictly increasing sequence < i1,i2, ..., ik > of indices of X such that for all j = 1,2,...,k, xij = zj. For example, Z = < a, b, f, c > is a subsequence of X = < a, b, c, f, b, c > with index sequence < 1, 2, 4, 6 >. Given two sequences X and Y the problem is to findthe length of the maximum-length common subsequence of X and Y.InputThe program input is from the std input. Each data set in the input contains two strings representing the given sequences. The sequences are separated by any number of white spaces. The input data are correct.OutputFor each set of data the program prints on the standard output the length of the maximum-length common subsequence from the beginning of a separate line.Sample Input

abcfbc         abfcab
programming    contest
abcd           mnp

Sample Output

4
2
0

#include<iostream>#include<string>using namespace std;string s1, s2;int length, len1, len2;void search(int l1, int l2, int len){if (len > length) length = len;if (length < len1 - l1 + len)for (int i = l1; i < len1; ++i)for (int j = l2; j < len2; ++j)if (s1[i] == s2[j])search(	i+1, j+1, len+1);}int main(){while(cin >> s1){cin >> s2;length = 0;len1 = s1.length();len2 = s2.length();search(0,0,0);cout << length << endl;}return 0;}

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