题解 | #牛牛的素数和#

#include <iostream>

using namespace std;

int sushu(int a);

int main()
{
    int l, r;
    int count = 0;
    cin >> l >> r;
    for (int j = l; j <= r; j++)
    {
        count += sushu(j);
    }
    cout << count << endl;
}

int sushu(int a)
{
    int count1 = 0;
    int flag = 0;
    if (a == 2)
    {
        return a;
    }
    else if (a == 1)
    {
        return 0;
    }
    for (int i = 2; i < a; i++)
    {
        if (a % i == 0)
        {
            return 0;
        }
        else
        {
            flag = 1;
        }
    }
    if (flag == 1)
    {
        return a;
    }
    return 0;
}