advent-of-code:

i attended advent of code with kevan and a few other recursers.

these are essentially puzzles; but really well crafted.

we did this one: https://adventofcode.com/2018/day/23

/*
[[x,y,z,r][x,y,z,r]]
*/
 
let posis = [
  [0, 0, 0, 4],
  [1, 0, 0, 1],
  [4, 0, 0, 3],
  [0, 2, 0, 1],
  [0, 5, 0, 3],
  [0, 0, 3, 1],
  [1, 1, 1, 1],
  [1, 1, 2, 5],
  [1, 3, 1, 1],
];
 
//find largest:
function get_max() {
  let max_posis_index = 0;
  for (let i = 0; i < posis.length; i++) {
    if (posis[i][3] > posis[max_posis_index][3]) {
      max_posis_index = i;
    }
  }
  return max_posis_index;
}
 
let max_r_index = get_max();
 
let in_range = solve(); 
 
console.log(in_range); 
 
function solve() {
  let count = 0;
 
  for (let i = 0; i < posis.length; i++) {
    let md = manhattan_distance(posis[i], posis[max_r_index]);
 
    if (md <= posis[max_r_index][3]){
        count++; 
    }
  }
  return count;
}
//p2 is the reference point.
function manhattan_distance(p1, p2) {
  let d = 0;
  for (let i = 0; i < p1.length - 1; i++) {
    let difference = p2[i] - p1[i];
    d += Math.abs(difference);
  }
  return d;
}
 

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it made me want to do these puzzles more, and use this as a way to get deeper into the nooks of programming.