#include <bits/stdc++.h>
using namespace std;
int n,ans;
string a[110];
long long binary(string n,int y){
	long long sum=0,t=1;
	for (int i=(int)n.size()-1;i>=0;i--){
		if (isalpha(n[i]))sum+=(n[i]-'A'+10)*t;
		else if (isdigit(n[i]))sum+=(n[i]-'0')*t;
		t*=y;
	}
	return sum;
}
bool isprime(long long x){
	for (int i=2;i<=sqrt(x);i++){
		if (x%i==0)return false;
	}
	return true;
}
int main(){
	cin>>n;
	for (int i=1;i<=n;i++){
		cin>>a[i];
		if (isprime(binary(a[i],2)))ans++;
	}
	cout<<ans;
	return 0;
}

鄙人程序3个Wonderful Answer（WA），请各位大佬改一下

#include <iostream>
#include <cmath>
using namespace std;
bool prime(int x){
    if(x<2)return false;
    for(int i=2;i*i<=x;i++)if(!(x%2))return false;
    return true;
}
int dec(string s){
    int sum=0;
    for(int i=0;i<s.length();i++)sum+=(s[i]-'0')*pow(2,s.length()-i-1);
    return sum;
}
int main(){
    int n,cnt=0;
    string s;
    cin>>n;
    for(int i=1;i<=n;i++){cin>>s;cnt+=prime(dec(s));}
    cout<<cnt<<endl;
    return 0;
}