coder by day, coder by night

Bloor CI 2026

shout out Mr. Mario

Useless code tips

Gives approximation of inverse square root of a number

more iterations -> higher precision

//Quake III hack in c++???
double invSqrt(double x) 
{
    int64_t i;
    double x2,y;
    const double threehalfs = 1.5;

    x2 = x * 0.5;
    y = x;
    memcpy(&i, &y, sizeof(i));              //evil floating point bit hack
    i = 0x5fe6ec85e7de30da - (i >> 1);      //what the frick
    memcpy(&y, &i, sizeof(y));  
    y = y * (threehalfs - (x2 * y * y));    //1st iteration
//  y = y * (threehalfs - (x2 * y * y));    //2nd iteration, can be removed

    return y;  
}

Milestones

200 points lets goo: September 26 2024

30 point (no cheese at all) : September 26 2024

40 point (Special thanks to my goat Sucram314) : April 23 2025

Leaderboard

Number 2 Submission: https://dmoj.ca/problem/coci11c1p2 October 5 2024

fastest C time and 2nd fastest time: https://dmoj.ca/problem/ccc24s4

NUMBER 2 ON 40P!?!?!? --> https://dmoj.ca/problem/phantomc1

NUMBER 1??? :O --> https://dmoj.ca/problem/3drotate

Future Bounties:

1. https://dmoj.ca/problem/ds5 -> Ac
2. https://dmoj.ca/problem/rubik -> 60-70% Ac
3. https://dmoj.ca/problem/utso15p6 -> 100% Ac
4. https://dmoj.ca/problem/phantomc1 -> 100% Ac DONE -> April 23 2025
5. https://dmoj.ca/problem/cco08p6 -> 25% Ac for now

Future Goals

• Hit Master on DMOJ and Codeforces
• Author a golfing problem
• Get perfect on CCC Senior