Cod sursa(job #2809150)

Utilizator Toaster_KeyboardMihaescu Vlad-Mihai Toaster_Keyboard Data 26 noiembrie 2021 08:18:11
Problema Factorial Scor 0
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.11 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("adunare.in");
ofstream fout("adunare.out");

long getZeroes(long a)
{
    long five = 5, zeroes = 0;
    while (five <= a * 5)
        zeroes += a / five, five *= 5;
    return zeroes;
}

long binSrc(const long& a)
{
    if (a == 0)
        return 1;
    long left = 1, right = a * 5;
    while (left <= right)
    {
        long middle = left + (right - left) / 2, zeroes = getZeroes(middle);
        if (zeroes == a)
            return middle;
        else if (zeroes < a)
            left = middle + 1;
        else if (zeroes > a)
            right = middle - 1;
    }
    return -1;
}

void solve()
{
    long a;
    fin >> a;
    long finding = binSrc(a);
    if (finding == 1 || finding == -1)
        fout << finding << '\n';
    else
        fout << finding - finding % 5 << '\n';
}

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    int t = 1;  fin >> t;
    while (t--)
    {
        solve();
    }

    return 0;
}
/*
    ifstream fin("input.in");
    ofstream fout("output.out");
*/