最简解法：

#include <bits/stdc++.h>
int n,a[105];
signed main(){std::cin>>n;
    for (int i=1;i<=n;i++){int x;std::cin>>x;a[x+50]++;if (a[x+50]>n/2){std::cout<<x;return 0;}}
    std::cout<<"no";}

#include <iostream>
int n,numz;
struct numt{int num,sum;}books[1005];
int look(int n1){
    for(int i=0;i<numz;i++)if(books[i].num==n1){books[i].sum++; if(books[i].sum>n/2)return 1; return 0;}
    books[numz].num=n1; numz++; return 0;}
int main(){
    std::cin>>n; for(int i=0;i<n;i++)books[i]={66,1};
    for(int i=0;i<n;i++){std::cin>>books[i].num; if(look(books[i].num)){std::cout<<books[i].num; return 0;};}
    for(int i=0;i<n;i++){if(books[i].sum>n/2){std::cout<<books[i].num; return 0;}} 
    std::cout<<"no"; return 0;}