Your 题解 is so difficult，see mine

#include<bits/stdc++.h>
int a[4],ans;
int main(){
	freopen("mid.in","r",stdin);
	freopen("mid.out","w",stdout);
	std::cin>>a[1]>>a[2]>>a[3];
	for(int i=1;i<=3;i++){  //不想用std::sort
		for(int j=1;j<=i;j++){  //冒泡模板
			if(a[i]<a[j]){
				std::swap(a[i],a[j]);
			}
		}
	}
	std::cout<<a[2];  //中间数
	return 0;
}