From 704c3bb7960fc40b3000d36e7ec6266747a9cc87 Mon Sep 17 00:00:00 2001
From: ironartisan <ironerhalo@gmail.com>
Date: Wed, 18 Aug 2021 22:33:42 +0800
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---
 problems/0084.柱状图中最大的矩形.md | 34 ++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/problems/0084.柱状图中最大的矩形.md b/problems/0084.柱状图中最大的矩形.md
index 941888db..bec3bc99 100644
--- a/problems/0084.柱状图中最大的矩形.md
+++ b/problems/0084.柱状图中最大的矩形.md
@@ -195,6 +195,40 @@ public:
 
 Java: 
 
+动态规划
+```java
+class Solution {
+    public int largestRectangleArea(int[] heights) {
+        int length = heights.length;
+        int[] minLeftIndex = new int [length];
+        int[] maxRigthIndex = new int [length];
+
+        // 记录左边第一个小于该柱子的下标
+        minLeftIndex[0] = -1 ;
+        for (int i = 1; i < length; i++) {
+            int t = i - 1;
+            // 这里不是用if，而是不断向右寻找的过程
+            while (t >= 0 && heights[t] >= heights[i]) t = minLeftIndex[t];
+            minLeftIndex[i] = t;
+        }
+        // 记录每个柱子 右边第一个小于该柱子的下标
+        maxRigthIndex[length - 1] = length;
+        for (int i = length - 2; i >= 0; i--) {
+            int t = i + 1;
+            while(t < length && heights[t] >= heights[i]) t = maxRigthIndex[t];
+            maxRigthIndex[i] = t;
+        }
+        // 求和
+        int result = 0;
+        for (int i = 0; i < length; i++) {
+            int sum = heights[i] * (maxRigthIndex[i] - minLeftIndex[i] - 1);
+            result = Math.max(sum, result);
+        }
+        return result;
+    }
+}
+```
+
 Python:
 
 动态规划