CSP201612-1 中间数

 

 

 

 

 1 //
 2 //  main.cpp
 3 //  CSP201612-1 中间数
 4 //
 5 //  Created by sylvia on 2021/11/4.
 6 //  Copyright © 2021 apple. All rights reserved.
 7 //
 8 
 9 #include <iostream>
10 #include <algorithm>
11 using namespace std;
12 #define M 1000+2
13 int a[M];
14 void fun(int i,int j,int mid){
15     while (a[i]==a[j]){
16                i--;j++;
17            }
18            if((a[i]==a[mid]&&a[j]!=a[mid])||(a[j]==a[mid]&&a[i]!=a[mid])) cout<<-1<<endl;
19            else cout<<a[mid]<<endl;
20 }
21 int main(){
22     int n;
23     cin>>n;
24     for (int i=0;i<n;i++){
25         cin>>a[i];
26     }
27     sort(a,a+n);
28     int mid=n/2;
29     if (n%2){  //奇数
30         fun(mid-1,mid+1,mid);
31     }
32     else if(!(n%2)){
33         fun(mid-1,mid,mid);
34     }
35     return 0;
36 }

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