import fs from "fs";

function range(first: number, second?: number) {
  const start = second ? first : 0;
  const end = second ? second : first;

  return new Array(end - start)
    .fill("fuck you js")
    .map((_wtf, index) => index + start);
}

const input = fs.readFileSync("input.txt").toString();

const array = input
  .split("\n")
  .flatMap((line) => line.split(""))
  .map(Number);

console.log(array);

const N = Math.sqrt(array.length);
console.assert(Math.round(N) === N, "Matrix should be square");

const visibilitySet = new Set<number>();

function lookup(startIndex: number, step: number) {
  range(N).reduce((acc, stepIndex) => {
    const currentIndex = startIndex + stepIndex * step;
    const item = array[currentIndex];

    if (item > acc) {
      visibilitySet.add(currentIndex);
      return item;
    }
    return acc;
  }, -1);
}

const edgeSize = N - 2;

// Down
range(1, 1 + edgeSize).map((index) => lookup(index, N));
// Up
range(1 + (N - 1) * N, 1 + edgeSize + (N - 1) * N).map((index) =>
  lookup(index, -N),
);
// Right
range(edgeSize)
  .map((v) => N * (v + 1))
  .map((index) => lookup(index, 1));

// Left
range(edgeSize)
  .map((v) => N * (v + 1) + N - 1)
  .map((index) => lookup(index, -1));

console.log(visibilitySet);
console.log(Array.from(visibilitySet.values()).length + 4);