uva 10453 补全回文并打印结果

uva 10453

#include<stdio.h>
#include<string.h>
#include<iostream>
#include<string>
#define N 1010
using namespace std;
int dp[N][N];
char a[N];
string print(int l,int r)
{
    string s="";
    if(l==r)
     {
         s+=a[l];
         return s;
     }
    if(l>r)
        return "";
    if(a[l]==a[r])
    {
        s=a[l]+print(l+1,r-1)+a[l];
    }
    else
    {
        if(dp[l+1][r]<=dp[l][r-1])
        {
            s=a[l]+print(l+1,r)+a[l];
        }
        else
            s=a[r]+print(l,r-1)+a[r];
    }
    return s;
}
int main()
{
    int i,j,k,l;
    while(~scanf("%s",a))
    {
        l=strlen(a);
        memset(dp,0,sizeof(dp));
        for(i=l-2;i>=0;i--)
        {
            for(j=i+1;j<l;j++)
            {
                if(a[i]==a[j])
                    dp[i][j]=dp[i+1][j-1];
                else
                    dp[i][j]=min(dp[i+1][j],dp[i][j-1])+1;
            }
        }
        printf("%d ",dp[0][l-1]);
        cout<<print(0,l-1)<<endl;
    }
    return 0;
}