LeetBook--队列&栈--01 矩阵

src/main/java/leet/book/queueStack/UpdateMatrix.java

@@ -0,0 +1,52 @@
+package leet.book.queueStack;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @author: 轩辕龙儿
+ * @date: 2021/7/2 15:49
+ * @Description: No Description
+ */
+public class UpdateMatrix {
+    public static void main(String[] args) {
+        Solution solution = new UpdateMatrix().new Solution();
+    }
+
+    class Solution {
+        public int[][] updateMatrix(int[][] mat) {
+            Queue<int[]> queue = new LinkedList<>();
+            int xLength = mat.length;
+            int yLength = mat[0].length;
+            boolean[][] use = new boolean[xLength][yLength];
+            for (int i = 0; i < xLength; i++) {
+                for (int j = 0; j < yLength; j++) {
+                    if (mat[i][j] == 0) {
+                        queue.offer(new int[]{i, j});
+                        use[i][j] = true;
+                    }
+                }
+            }
+            int[][] ops = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
+            while (!queue.isEmpty()) {
+                int[] temp = queue.poll();
+                int x = temp[0];
+                int y = temp[1];
+                for (int[] op : ops) {
+                    int tx = x + op[0];
+                    int ty = y + op[1];
+                    if (tx >= 0 && tx < xLength && ty >= 0 && ty < yLength && !use[tx][ty]) {
+                        mat[tx][ty] = mat[x][y] + 1;
+                        queue.offer(new int[]{tx,ty});
+                        use[tx][ty]=true;
+                    }
+                }
+            }
+            return mat;
+        }
+    }
+}