Common Subsequence

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 24919    Accepted Submission(s): 11035


Problem Description A 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 find the length of the maximum-length common subsequence of X and Y. 
The program input is from a text file. Each data set in the file contains two strings representing the given sequences. The sequences are separated by any number of white spaces. The input data are correct. For 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 題目沒看完 看了一下樣例 估計是最長公共子序列。。 雖然水題  還是記不牢 寫一遍

#include <cstdio>  
#include <cstdlib>  
#include <cmath>  
#include <cstring>  
#include <ctime>  
#include <algorithm>  
#include <iostream>
#include <sstream>
#include <string>
#define oo 0x13131313   
using namespace std;
char A[1001],B[1001];
int F[1000][1000];
void solve()
{
		memset(F,0,sizeof(F));
		int lena=strlen(A);
		int lenb=strlen(B);
		F[0][0]=0;
		F[0][1]=0;
		F[1][0]=0;
		for(int i=1;i<=lena;i++)
		 for(int j=1;j<=lenb;j++)
	{
		 if(A[i-1]==B[j-1])
		 F[i][j]=F[i-1][j-1]+1;
		 else F[i][j]=max(F[i][j-1],F[i-1][j]);
	}
		printf("%d\n",F[lena][lenb]);
}
int main()
{
	while(scanf("%s %s",A,B)!=EOF)
	{
		solve();
	}
	return 0;
}