https://school.programmers.co.kr/learn/courses/30/lessons/161990/solution_groups?language=javascript
function solution(wallpapers: string[]) {
let minX: number | null = null;
let maxX: number | null = null;
let minY: number | null = null;
let maxY: number | null = null;
for (const [i, wallpaper] of wallpapers.entries()) {
for (const [j, char] of [...wallpaper].entries()) {
if (char === "#") {
if (minX === null || minX > i) minX = i;
if (minY === null || minY > j) minY = j;
if (maxX === null || maxX < i) maxX = i;
if (maxY === null || maxY < j) maxY = j;
}
}
}
return [minX, minY, maxX! + 1, maxY! + 1];
}