c++随机输入8位密码（大小写、数字）

这样改：

#include<iostream>
#include<conio.h>
#include<cstdlib>
#include<ctime>
#include<limit>
#include<cctype>
using namespace std;

int main(){
unsigned char ch='a';
int n=1;
srand(static_cast<unsigned int>(time(NULL)));

for (;n<=8;){
ch=static_cast<unsigned char>(rand());
if(!isalnum(ch)) continue;
cout<<ch;
n++;
}

cout<<" ";

getch();
return 0;
}