代码如下：

#include <iostream>
using namespace std;
int s,n,a[1005],b[55],c;
int main(){
    cin>>s>>n;
    for (int i=0; i<n; i++) cin>>a[i];
    for (int i=0; i<s; i++){
        b[i]=i;
        for (int j=0; j<n; j++)
            if(a[j]==b[i]) b[i]=-1;
    }
    for (int i=0; i<s; i++)
        if(b[i]==-1) c++;
    if(c==s){
        cout<<s;
    }else{
        for (int i=0; i<s; i++){
            if(b[i]==-1) continue;
            else cout<<b[i]<<' ';
        }
    }
}

dalao求助！ 有关注！有关注！有关注！