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nonprimefactors.cpp
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nonprimefactors.cpp
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#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
vector<int> fact(2000001, 0);
vector<bool> primes(2000001, true);
primes[0] = primes[1] = false;
for (int x = 2; x * x <= 2000001; x++)
if (primes[x])
for (int a = x + x; a < 2000001; a += x)
primes[a] = false;
int cases;
cin >> cases;
while (cases-- > 0) {
int num;
cin >> num;
if (fact[num] != 0) {
cout << fact[num] << '\n';
continue;
}
if (primes[num]) {
cout << 1 << '\n';
continue;
}
int original = num;
int uniquePrimes = 0, factors = 1;
if ((num & 1) == 0) {
uniquePrimes++;
int count = 0;
while ((num & 1) == 0) {
count++;
num >>= 1;
}
factors *= count + 1;
}
if (primes[num]) {
uniquePrimes++;
factors <<= 1;
} else {
for (int x = 3; x <= sqrt(num); x += 2)
if (num % x == 0) {
uniquePrimes++;
int count = 0;
while (num % x == 0) {
count++;
num /= x;
}
factors *= count + 1;
}
if (primes[num]) {
uniquePrimes++;
factors <<= 1;
}
}
fact[original] = factors - uniquePrimes;
cout << fact[original] << '\n';
}
return 0;
}