hdu 3183 A Magic Lamp 贪心

#include <stdio.h>#include <string.h>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <stack>#include <set>#include <map>#include <string>#include <math.h>#include <stdlib.h>#include <time.h>using namespace std;int main(){    char s[1024];    int i,j,st,n,m,ans,p,f;    while(~scanf("%s%d",s,&m))    {        n=strlen(s);        st=0;        f=0;        for(i=n-m;i>0;i--)        {            ans=10;            for(j=st;j<n-i+1;j++)            {                if(ans>s[j]-'0')                {                    ans=s[j]-'0';                    p=j+1;                }            }            if(ans!=0) f=1;            if(f==0&&ans==0) ;            else printf("%d",ans);            st=p;        }        if(f==0) printf("0");        printf("\n");    }    return 0;}