python/TangDou/Topic/Mobius/P4318.cpp

#include <bits/stdc++.h>
using namespace std;
int t, k, z[100005], p[100005], mu[100005];
long long check(long long g) {
    long long res = 0;
    for (int i = 1; i * i <= g; i++)
        res = res + mu[i] * (g / i / i);

    return res;
}
int main() {
    mu[1] = 1;
    for (int i = 2; i <= 100000; i++) {
        if (!z[i]) {
            p[++p[0]] = i;
            mu[i] = -1;
        }
        for (int j = 1; j <= p[0] && i * p[j] <= 100000; j++) {
            z[i * p[j]] = 1;
            if (i % p[j] == 0) {
                mu[i * p[j]] = 0;
                break;
            }
            mu[i * p[j]] = -mu[i];
        }
    }
    cin >> t;
    while (t--) {
        cin >> k;
        long long l = 1, r = 2e9, mid, vt;
        while (l <= r) {
            mid = (l + r) / 2;
            vt = check(mid);
            if (vt < k)
                l = mid + 1;
            else
                r = mid - 1;
        }
        cout << r + 1 << endl;
    }
    return 0;
}