每日一题

Author: Dagon0577

README.md

@@ -63,6 +63,7 @@
 
   - [思路](https://leetcode-cn.com/problems/super-egg-drop/solution/ji-ben-dong-tai-gui-hua-jie-fa-by-labuladong/)
   - [视频（李永乐nb）](https://www.youtube.com/watch?v=mLV_vOet0ss&t=68s)
+- [542. 01 矩阵](https://github.com/Dagon0577/LeetCode/blob/master/力扣每日一题/542.%2001%20矩阵.java)
 
 ## leetcode周赛
 

力扣每日一题/542. 01 矩阵.java

@@ -0,0 +1,39 @@
+class Solution {
+    public int[][] updateMatrix(int[][] matrix) {
+        int n = matrix.length;
+        int m = matrix[0].length;
+        int[][] dp = new int[n][m];
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < m; j++) {
+                if (matrix[i][j] == 0) {
+                    dp[i][j] = 0;
+                } else {
+                    dp[i][j] = n + m;
+                }
+            }
+        }
+        // 只有 水平向左移动 和 竖直向上移动
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < m; j++) {
+                if (i - 1 >= 0) {
+                    dp[i][j] = Math.min(dp[i][j], dp[i - 1][j] + 1);
+                }
+                if (j - 1 >= 0) {
+                    dp[i][j] = Math.min(dp[i][j], dp[i][j - 1] + 1);
+                }
+            }
+        }
+        // 只有 水平向左移动 和 竖直向下移动
+        for (int i = n - 1; i >= 0; i--) {
+            for (int j = m - 1; j >= 0; j--) {
+                if (i + 1 < n) {
+                    dp[i][j] = Math.min(dp[i][j], dp[i + 1][j] + 1);
+                }
+                if (j + 1 < m) {
+                    dp[i][j] = Math.min(dp[i][j], dp[i][j + 1] + 1);
+                }
+            }
+        }
+        return dp;
+    }
+}