/**
* @param {character[][]} matrix
* @return {number}
*/
let maximalSquare = function (matrix) {
let maxY = matrix.length
if (!maxY) return 0
let maxX = matrix[0].length
let dp = []
let max = 0
let dpBasic = (y, x) => {
if (matrix[y][x] === "1") {
max = 1
dp[y][x] = 1
} else {
dp[y][x] = 0
}
}
for (let y = 0; y < maxY; y++) {
dp[y] = []
dpBasic(y, 0)
}
for (let x = 1; x < maxX; x++) {
dpBasic(0, x)
}
for (let y = 1; y < maxY; y++) {
for (let x = 1; x < maxX; x++) {
let val = matrix[y][x]
if (val === "0") {
dp[y][x] = 0
} else {
let left = dp[y][x - 1]
let top = dp[y - 1][x]
let leftTop = dp[y - 1][x - 1]
dp[y][x] = Math.min(left, top, leftTop) + 1
max = Math.max(max, dp[y][x])
}
}
}
return max * max
}
