Update 单调栈.md

add Java solution for Leetcode 739. Daily Temperatures

数据结构系列/单调栈.md

@@ -181,4 +181,19 @@ vector<int> nextGreaterElements(vector<int>& nums) {
 <img src="../pictures/qrcode.jpg" width=200 >
 </p>
 
-======其他语言代码======
\ No newline at end of file
+======其他语言代码======
+// 739. Daily Temperatures
+class Solution {
+    public int[] dailyTemperatures(int[] T) {
+        Stack<Integer> stack = new Stack<>();
+        int[] ans = new int[T.length];
+        for (int i = 0; i < T.length; i++) {
+            while (!stack.isEmpty() && T[i] > T[stack.peek()]) {
+                int index = stack.pop();
+                ans[index] = i - index;
+            }
+            stack.push(i);
+        }
+        return ans;
+    }
+}