diff --git a/src/main/java/com/cool/hot100/graph/Num994.java b/src/main/java/com/cool/hot100/graph/Num994.java
new file mode 100644
index 0000000..febbc4d
--- /dev/null
+++ b/src/main/java/com/cool/hot100/graph/Num994.java
@@ -0,0 +1,65 @@
+package com.cool.hot100.graph;
+
+import java.util.ArrayDeque;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Queue;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/09/03/14:25
+ * DayNumber 3
+ * Hard 2
+ * Level ?
+ */
+public class Num994 {
+
+    int[] rowChange = new int[] { 0, 1, -1, 0 };
+    int[] columnChange = new int[] { 1, 0, 0, -1 };
+
+    public int orangesRotting(int[][] grid) {
+        int rowLength = grid.length;
+        int columnLength = grid[0].length;
+        Queue<Integer> queue = new ArrayDeque<>();
+        Map<Integer, Integer> map = new HashMap<>();
+        for (int i = 0; i < rowLength; i++) {
+            for (int j = 0; j < columnLength; j++) {
+                if (grid[i][j] == 2) {
+                    int code = i * columnLength + j;
+                    queue.add(code);
+                    map.put(code, 0);
+                }
+            }
+        }
+        int res = 0;
+        while (!queue.isEmpty()) {
+            Integer code = queue.poll();
+            int row = code / columnLength;
+            int column = code % columnLength;
+            for (int i = 0; i < 4; i++) {
+                int cRow = row + rowChange[i];
+                int cColumn = column + columnChange[i];
+                if (cRow >= 0 && cRow < rowLength && cColumn >= 0 && cColumn < columnLength
+                        && grid[cRow][cColumn] == 1) {
+                    grid[cRow][cColumn] = 2;
+
+                    int cCode = cRow * columnLength + cColumn;
+                    queue.add(cCode);
+                    map.put(cCode, map.get(code) + 1);
+                    res = map.get(cCode);
+                }
+            }
+        }
+        for (int[] ints : grid) {
+            for (int j = 0; j < columnLength; j++) {
+                if (ints[j] == 1) {
+                    return -1;
+                }
+            }
+        }
+        return res;
+    }
+
+}