poj 1458 Common Subsequence

/* Name: poj 1458 Common Subsequence Author: Unimen Date: 10/05/2011 19:18 Description: DP 最长公共子序列*//*解题报告：转移方程: dp(i,j) = dp(i-1, j-1)+1 i==j max(dp(i-1,j), dp(i, j-1)) i!=j*/#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;char a[1000], b[1000];int num[1000][1000];int main(){int i, j;while(scanf("%s%s", a+1, b+1) != EOF){for(i=0; i<=strlen(a+1); ++i){num[i][0] = 0;}for(i=0; i<=strlen(b+1); ++i){num[0][i] = 0;}for(i=1; i<=strlen(a+1); ++i){for(j=1; j<=strlen(b+1); ++j){if(a[i] == b[j]){num[i][j] = num[i-1][j-1] + 1;}if(a[i] != b[j]){num[i][j] = max(num[i-1][j], num[i][j-1]);}}}cout<<num[strlen(a+1)][strlen(b+1)]<<endl;}return 0;}