https://www.luogu.com.cn/problem/P1106
这 * 的 *贪心模拟搞我两小时吐了555555555~

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
string s;
int k,tmp,ans[300],cnt,minn,first0,head;
int main(){
    cin>>s>>k;
    int w=k;
    while(first0<k){
        //cout<<first0<<" "<<k<<endl;
        k-=first0;
        head+=first0;
        while(s[head]-'0'==0) head++;
        first0=0;
        for(int i=head;i<s.size();i++){
            if(s[i]-'0'==0){
                first0=i-head;
                //cout<<first0<<endl;
                break;
            } 
        }
        if(first0==0) break;
    }
    //cout<<k<<" ";
    first0=0;
    for(int i=head;i<s.size();i++){
        if(s[i]-'0'==0){
            first0=i-head+1;
            break;
        } 
    }
    // first0>k正常做 
    //cout<<head<<" "<<first0<<" ";
    if(first0==k){
        int flag=0;
        for(int i=k;i<s.size();i++){
            if(s[i]-'0') flag=1;
            if(flag) cout<<s[i]-'0';
        }
        return 0;
    }


    int finished=0;
    for(int i=head;i<=s.size()-1;i++){
        //cout<<k<<endl;
        if(s.size()-w==cnt) break;
        if(!k){
            for(int j=i;j<=s.size()-1;j++) ans[++cnt]=s[j]-'0';
            finished=1;
        }
        if(finished) break;
        minn=0x3f3f3f3f;
        for(int j=i;j<=s.size()-1&&j<=i+k;j++){
            if(s[j]-'0'<minn){
                minn=s[j]-'0';
                tmp=j;
            }
        }
        //cout<<tmp<<" ";
        k-=(tmp-i);
        //cout<<k<<" ";
        ans[++cnt]=minn;
        i=tmp;
        //cout<<i<<endl;
    }
    //cout<<cnt<<endl;
    for(int i=1;i<=cnt;i++) cout<<ans[i];
    return 0;
}