part1.ts

import * as fs from 'fs';

const input = fs
	.readFileSync('input', 'utf8')
	.split('\n')
	.map((x) => x.split('').map((y) => ({ height: +y, visible: false })));

const calcVisibility = (tree, max) => {
	if (tree.height > max) {
		tree.visible = true;
		max = tree.height;
	}
	return max;
};

for (let i = 0; i < input.length; i++) {
	// each row
	for (let j = 0, max = -1; j < input[i].length; j++) {
		// left to right
		max = calcVisibility(input[i][j], max);
	}
	for (let j = input[i].length - 1, max = -1; j >= 0; j--) {
		// right to left
		max = calcVisibility(input[i][j], max);
	}
}
for (let j = 0; j < input[0].length; j++) {
	// each column
	for (let i = 0, max = -1; i < input.length; i++) {
		// top to bottom
		max = calcVisibility(input[i][j], max);
	}
	for (let i = input.length - 1, max = -1; i >= 0; i--) {
		// bottom to top
		max = calcVisibility(input[i][j], max);
	}
}

let result = 0;

input.forEach((line) => (result += line.filter((x) => x.visible).length));

console.log(result);