#include <iostream>
using namespace std;
int main()
{
    int n, p, x = 0;
    cin >> n;
    for (int i = 2; i <= n; i++)
    {
        p = 1;
        for (int j = 2; j < i; j++)
        {
            if (i % j == 0)
            {
                p = 0;
                break;
            }
        }
        if (p == 1)
        {
            cout << i << " ";
            x += 1;
            if (x % 5 == 0)
            {
                cout << endl;
            }
        }
    }
    return 0;
}

点赞的都是大帅哥、大美女哟！

直接暴力的求素数，当然也可以是用埃氏筛或欧式筛

#include <bits/stdc++.h>
using namespace std;
int isprime(int n)
{
    if (n == 1)
        return false;
    for (int i = 2; i <= sqrt(n); i++)
        if (n % i == 0)
            return false;
    return true;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, num = 0;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        if (num == 5)
        {
            cout << endl;
            num = 0;
        }
        if (isprime(i))
        {
            cout << i << " ";
            num++;
        }
    }
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int n,a[1005],cnt;
bool check(int x)//判断素数
{
    if(x==1) return false;
    for(int i=2;i<x;i++)
        if(x%i==0)
            return false;
    return true;
}
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        if(check(i))//把素数存入a数组里
        {
            cnt++;
            a[cnt]=i;
        }
    }
    int x;
    for(int i=1;i<=cnt;i++)
    {
        x++;
        cout<<a[i]<<" ";//输出素数
        if(x==5)//当x为5换行
        {    
            cout<<endl;
            x=0;//把x清零
        }
    }
    return 0;
}

#include <iostream>#include <cmath>usingnamespacestd; int main() { int n; cin >> n; int num = 0; for (int i = 1; i <= n; i++) { int judge = 1; if (i == 1)//1既不是质数也不是合数 { continue; } for (int j = 2; j <= sqrt(i); j++) { if (judge == 0) { continue; } if (i % j == 0) { judge = 0; } } if (judge == 1) { cout << i << " "; num++; if (num == 5) { cout << endl; num = 0; } } } return0; }

#include <cmath>
using namespace std;
bool isPrime(int a){
	if(a < 2){
		return false;
	}
	for(int i=2;i<=sqrt(a);i++){
		if( a%i == 0 ){
			return false;
		}
	}
	return true;
}
int main(){
	int n; cin >> n; int k=0;
	for(int p=1;p<=n;p++){
		
		if(k%5 == 0){
			cout << endl;
		}
		if(isPrime(p) == true){
			cout << p <<" ";
			k++;
		}
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int a,sum;
int main()
{
    cin>>a;
    for(int i=2;i<a;i++)
    {
        int num=0;
        for(int j=2;j<i;j++)
        {
            if(i%j==0)
            {
                num=1;
            }
        }
        if(num==0)
        {
            if(sum==5)
            {
                cout<<endl;
                sum=1;
                cout<<i<<" ";
            }
            else
            {
                sum++;
                cout<<i<<" ";
            }
            
        }
    }
    return 0;
}

素数表

#include<bits/stdc++.h>
using namespace std;
bool f[1007];
int p[1007],num;
int main()
{
    int n;
    cin>>n;
    memset(f,1,sizeof(f));
    for (int i=2;i<=n;i++)
        if (f[i])
        {
            p[++num]=i;
            for (int j=i;j<=n;j+=i)
                f[j]=0;
        }
    for (int i=1;i<=num;i++)
    {
        cout<<p[i]<<" ";
        if (i%5==0)
            cout<<'\n';
    }
    return 0;
}

#include <bits/stdc++.h> 
using namespace std;
int main()
{
    int n, num = 0;
    cin >> n;
    for (int i = 2; i <= n; i++)
    {
        bool flag = true;
        for (int j = 2; j < i; j++)
        {
            if (i % j == 0)
            {
                flag = false;
            }
        }
        if (flag)
        {
            num++;
            if (num > 5)
            {
                cout << endl;
                num = 1;
            }
            cout << i << " ";
        }
    }
    return 0;
}

我有一个办法：把上一题的答案搬来，改动一下即可^_^……

def aps(a):
    for i in range(2,a//2+1):
        if a%i == 0:
            return False
    return True#封装函数
a=input()
M=int(a)
p=[]
s=[]
for i in range(2,M+1):
    if aps(i):
        s.append(i)
    #P64改装一下即可
p=0
for i in s:
    if p<4:
        print(i,end=' ')
        p+=1
    else:
        print(i)#自动换行
        p=0#一定要初始化原因DDDD

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