题解 | #约数的个数#

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

vector<int> vetp;//质数数组
bool is_p(int x) { //判定质数
    for (int j = 2; j < (int)sqrt(x) + 1; j++) {
        if (x % j == 0) {
            return false;
        }
    }
    return true;
}
void vetp_add() {
    // 扩容vetp
    for (int i = *vetp.rbegin() + 2;; i += 2) {
        if (is_p(i)) {
            vetp.push_back(i);
            return;
        }
    }
}
int main() {
    vetp.push_back(2);
    vetp.push_back(3);
    int n;
    cin >> n;
    while (n--) {
        map<int, int> mii;
        int num;
        cin >> num;
        int vetp_index = 0;
        long long cnt = 1;
        while (num != 1) {
            if (vetp_index == vetp.size() - 1) {
                if (is_p(num)) {
                    mii[num]++; break;
                }
                else {
                    vetp_add();
                }

            }
            while (num % vetp[vetp_index] == 0) {
                mii[vetp[vetp_index]]++;
                num /= vetp[vetp_index];
            }
            vetp_index++;
        }
        for (auto i = mii.begin(); i != mii.end(); i++) {
            cnt *= (i->second + 1);

        }
        cout << cnt << endl;
    }
}
// 64 位输出请用 printf("%lld")