素数判断 按从小到大输出m和n之间的素数,逗号间隔，如果之间没有素数，则输出NO

按从小到大输出m和n之间的素数,逗号间隔，如果之间没有素数，则输出NO

下面是我的一个实现，供参考：

#include <stdio.h>

int main(void){
    
    int m,n;
    scanf("%d %d",&m,&n);
    
    int temp;
    if(m<0){
        m=2;
    }
    
    if(n<0){
        n=2;
    }
    
    if(n<m){
        temp = m;
        m=n;
        n=temp;
    }
    
//    printf("m=%d,n=%d\n",m,n);
    
    int i,j;
    int prime=1;
    int havePrime = 0;
    
    for(i=m;i<=n;i++){
        
        for(j=2;j<i-1;j++){
            
            if(i%j==0){                
                prime=0;
            //    printf("prime=%d,i=%d,j=%d\n",prime,i,j);
                break;
            }
        }
        
        if(prime==1&&i>1){
            printf("%d,",i);
            havePrime=1;
        }
        
        prime=1;
    }
    
    if(havePrime==0){
        printf("NO");
    }
    
    return 0;
} 

#include <QCoreApplication>
#include <iostream>
#include <math.h>
using namespace std;

bool isPrime(int number)
{
    int i;  // 循环次数
    int k;  // m 的平方根
    k=(int)sqrt( (double)number );
    for(i=2;i<=k;i++)
        if(number%i==0)
            break;
    if(i>k)
        return true;
    else
        return false;
}

int main()
{
    vector<int> preCount;
    int max,min;
    cout<<"Please inPut min";
    cin>>min;
    cout<<"Please inPut max";
    cin>>max;

    if(min>max)
    {
        return 0;
    }
    else
    {
        bool ispre=false;
        for(int i=min;i<=max;++i)
        {
            ispre=isPrime(i);
            if(ispre)
            {
                preCount.push_back(i);
            }
        }
    }
    if(0==preCount.size())
    {
        cout<<"No"<<endl;
    }
    else
    {
        for(int i=0;i<preCount.size();++i)
        {
            cout<<"  "<<preCount[i];
        }
        cout<<endl;
    }

}

#include <stdio.h>
int f(int n)
{
    if(n==2) return 1;
    for(int j=2;j*j<=n;j++)
    {
        if(n%j==0) return 0;
    }
    return 1;
}
int main()
{
    int m,n,flag=0;
    scanf("%d%d",&m,&n);
    for(int j=m;j<=n;j++)
    if(f(j)==1) 
    {
        printf("%d ",j);
        flag++;
    }
    if(flag==0)
    printf("NO");
    return 0;
}

素数筛选使用了埃氏筛法

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

int main()
{
    int m = 1, n = 10;
    cout << "please input m = ";
    cin >> m;
    cout << "please input n = ";
    cin >> n;

    if (m > n){
        int temp = n;
        n = m;
        m = temp;
    }

    bool* nums = new bool[n + 1];
    memset(nums, true, n + 1);
    nums[0] = false;
    //素数计算-埃氏筛法
    for (int i = 2; i <= n; ++i) {
        if (nums[i] == false) {
            continue;
        }
        for (int j = i + i; j <= n; j += i) {
            nums[j] = false;
        }
    }
    //判断
    int count = 0;
    for (int i = m; i < n; ++i) {
        if (nums[i] == true){
            if (count != 0){
                cout << ",";
            }
            cout << i;
            ++count;
        }
    }
    if (count == 0){
        cout << "NO";
    }
    cout << endl;
    //delete[] nums;
    system("pause");
    return 0;
}