Time: 47 ms (67.24%), Space: 58.9 MB (80.95%) - LeetHub

Author: chappdev2019

0542-01-matrix/0542-01-matrix.js

@@ -0,0 +1,29 @@
+/**
+ * @param {number[][]} mat
+ * @return {number[][]}
+ */
+var updateMatrix = function (mat) {
+    let m = mat.length, n = mat[0].length;
+    let queue = [];
+    let directions = [[1, 0], [-1, 0], [0, 1], [0, -1]]; 
+    for (let i = 0; i < m; i++) {
+        for (let j = 0; j < n; j++) {
+            if (mat[i][j] === 0) {
+                queue.push([i, j]); 
+            } else {
+                mat[i][j] = -1; 
+            }
+        }
+    }
+    while (queue.length) {
+        let [x, y] = queue.shift(); 
+        for (let [dx, dy] of directions) {
+            let nx = x + dx, ny = y + dy;
+            if (nx < 0 || ny < 0 || nx >= m || ny >= n || mat[nx][ny] != -1) continue;
+            mat[nx][ny] = mat[x][y] + 1; 
+            queue.push([nx, ny]); 
+        }
+
+    }
+    return mat;
+};