学习C,从书中寻找对该项目的澄清

// Find all prime numbers between 1 and 100

#include <iostream>
#include <cmath>
using namespace std;

    int main()
    {
        int counter; // loop counter
        int count_two; // counter for second loop
        int val; // equals the number of count,used in division to check for primes
        bool check;

        check = true;

        for(counter = 1; counter <= 100; counter++){
            val = counter;
                for(count_two = 2; count_two <= 9; count_two++){
                    if((val % count_two) == !(check)){
                        cout << val << " is a prime number.n";
                }
          }
    }
    return 0;
}
// program didn't work properly because of needless complication; all that needs to be checked for is whether a number is divisible by two

/*
*********correct code***********
#include <iostream>
using namespace std;
int main()
{
    int i,j;
    bool isprime;
    for(i=1; i < 100; i++) {
        isprime = true;
    // see if the number is evenly divisible
    for(j=2; j <= i/2; j++)
    // if it is,then it is not prime
        if((i%j) == 0) isprime = false;
        if(isprime) cout << i << " is prime.n";
}
return 0;
}
********************************
*/

从我可以收集的信息来看,我在这里是一条相当正确的道路.我认为我使用双循环和过度使用变量使事情变得复杂,这可能导致程序工作不正确 – 如果需要我可以发布输出,但这肯定是错误的.

我的问题基本上是这样的：我到底出错了什么地方？我不需要有人来重做这个,因为我想自己更正代码,但我已经看了一段时间,并且无法弄清楚为什么我的工作不起作用.此外,由于我对此不熟悉,因此任何有关语法/可读性的输入都会有所帮助.提前致谢.