NEU(1262: ASCII Sequence II)动态规划

http://acm.neu.edu.cn/hustoj/problem.php?id=1262

#include <iostream>
#include <stdio.h>
#include <string>
#include <string.h>
#include <algorithm>
#include <math.h>
#include <fstream>
#include <vector>
#include <map>
#include <queue>
#include <stack>
#include <math.h>
#include <stdlib.h>
#include <set>
#include <math.h>
#include <sstream>
using namespace std ;
const int maxn = 1005;
int dp[maxn][maxn];
int min(int a,int b){
    return a>b?b:a;
}
string s1,s2;
int main(){
    while(cin>>s1>>s2){
        int len_s1 = s1.size();
        int len_s2 = s2.size();
        int sum = 0;
        for(int i = 0;i < len_s2;i++){
            sum += abs(s1[i] - s2[i]);
            dp[i][i] = sum;
        }
        dp[0][0] = abs(s2[0] - s1[0]);
        for(int i = 1;i < len_s1;i++)
            dp[0][i] = min(dp[0][i-1],abs(s2[0] - s1[i]));
        for(int i = 1;i < len_s2;i++){
            for(int j = i+1;j < len_s1;j++){
                dp[i][j] = min(dp[i][j-1],dp[i-1][j-1] + abs(s2[i] - s1[j]));
            }
        }
        /*for(int i = 0;i < len_s2;i++){
            for(int j = 0;j < len_s1;j++)
                printf("%d ",dp[i][j]);
            printf("\n");
        }*/
        printf("%d\n",dp[len_s2 - 1][len_s1 - 1]);
    }
    return 0;
}