20分求助

#include<iostream>
#include<cstring>
#include<string>
#include<cstdio>
#include<queue>
#include<cmath>
#include<algorithm>
using namespace std;
int n,m,a[90000000],book[90000000],minn=999999999;
int main(){
    cin >>n>>m; 
    book[0]=0;
    for(int i=0;i<n;i++){
        minn=999999999;
        cin >>a[i];
        for(int j=i-1;j>=i-m;j--){
            if(a[j]<minn&&a[j]!=0){
                minn=a[j];
            }
        }
        book[i]=minn;

    }
    for(int i=0;i<n;i++){
        if(book[i]==999999999){
            book[i]=0;
        }
        cout <<book[i]<<endl;
    }
    return 0;
}