FizzFuzzPrimeQ3 test

fizzfuzztestQ3.cpp

// Online C++ compiler to run C++ program online
#include <iostream>
#include <string>
#include <vector>

using namespace std;



vector<string> sol(long n)
{
    const long n1 = n-1;
    
    // lookup prime
    bool* not_primes = new bool[n+3]; // safe guard
    not_primes[1-1]=true;
    not_primes[2-1]=false;
    // init
    for(long i = 3-1; i<n1; i+=2) not_primes[i]=false;
    // 2 first, pair numbers
    for(long i = 4-1; i<n1; i+=2)
        not_primes[i]=true;
    for(long i = 3-1; i<n1; i++)
    {
        if(not_primes[i++])
            continue;
        // cout << i << "\n";
        for(long j=2*i-1; j<n1; j+=i)
        {
            not_primes[j]=true;
        }
    }
    
    // for(long i = 0; i <n1; i++)
    // {
    //     cout << i+1 << " " << not_primes[i] << "\n";
    // }
    
    vector<string> res;
    
    res.resize(n1);
    // to avoid using j%3 or j%5
    long i3=3-1;
    long i5 =5-1;

    for(long j = 0; j<n1;j++)
    {
        if(!not_primes[j])
        {
            res[j]="Prime";
            // update indices
            if(j == i3) i3+=3;
            if(j == i5) i5+=5;
            continue;
        }
        
        if(j == i3)
        {
            res[j]="Fizz";
            i3+=3;
        }
        if(j == i5)
        {
            res[j]+="Fuzz";
            i5+=5;
            continue;
        }
        if(res[j].size() == 0)
            res[j] = to_string(j+1);
       
    }
    
    delete[] not_primes;
    
    return res;
}

int main() {
    // Write C++ code here
    auto res = sol(121);
    //cout << "h2\n";
    cout << "res size: " << res.size() <<"\n";
    for(const string v : res)
    {
        cout << v << "\n";
    }

    return 0;
}