From b22425c859269c5862149a8f736bcf0c3e5e00eb Mon Sep 17 00:00:00 2001
From: Relsola <sola001018@gmail.com>
Date: Mon, 25 Dec 2023 22:55:12 +0800
Subject: [PATCH] =?UTF-8?q?Update=200084.=E6=9F=B1=E7=8A=B6=E5=9B=BE?=
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---
 problems/0084.柱状图中最大的矩形.md | 66 ++++++++++++--------
 1 file changed, 40 insertions(+), 26 deletions(-)

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 97dab4f3..b836705a 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
@@ -515,27 +515,31 @@ func largestRectangleArea(heights []int) int {
 var largestRectangleArea = function(heights) {
     const len = heights.length;
     const minLeftIndex = new Array(len);
-    const maxRigthIndex = new Array(len);
+    const maxRightIndex = new Array(len);
     // 记录每个柱子 左边第一个小于该柱子的下标
     minLeftIndex[0] = -1; // 注意这里初始化，防止下面while死循环
     for(let i = 1; i < len; i++) {
         let t = i - 1;
         // 这里不是用if，而是不断向左寻找的过程
-        while(t >= 0 && heights[t] >= heights[i]) t = minLeftIndex[t];
+        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[len - 1] = len; // 注意这里初始化，防止下面while死循环
+    maxRightIndex[len - 1] = len; // 注意这里初始化，防止下面while死循环
     for(let i = len - 2; i >= 0; i--){
         let t = i + 1;
         // 这里不是用if，而是不断向右寻找的过程
-        while(t < len && heights[t] >= heights[i]) t = maxRigthIndex[t];
-        maxRigthIndex[i] = t;
+        while (t <= n && heights[t] > heights[i]) {
+			t = maxRightIndex[t];
+		}
+        maxRightIndex[i] = t;
     }
     // 求和
     let maxArea = 0;
     for(let i = 0; i < len; i++){
-        let sum = heights[i] * (maxRigthIndex[i] - minLeftIndex[i] - 1);
+        let sum = heights[i] * (maxRightIndex[i] - minLeftIndex[i] - 1);
         maxArea = Math.max(maxArea , sum);
     }
     return maxArea;
@@ -543,27 +547,37 @@ var largestRectangleArea = function(heights) {
 
 //单调栈
 var largestRectangleArea = function(heights) {
-    let maxArea = 0;
-    const stack = [];
-    heights = [0,...heights,0]; // 数组头部加入元素0 数组尾部加入元素0
-    for(let i = 0; i < heights.length; i++){
-        if(heights[i] > heights[stack[stack.length-1]]){ // 情况三
-            stack.push(i);
-        } else if(heights[i] === heights[stack[stack.length-1]]){ // 情况二
-            stack.pop(); // 这个可以加，可以不加，效果一样，思路不同
-            stack.push(i);
-        } else { // 情况一
-            while(heights[i] < heights[stack[stack.length-1]]){// 当前bar比栈顶bar矮
-                const stackTopIndex = stack.pop();// 栈顶元素出栈，并保存栈顶bar的索引
-                let w = i - stack[stack.length -1] - 1;
-                let h = heights[stackTopIndex]
+	let maxArea = 0;
+	const stack = [0];
+	heights.push(0);
+	const n = heights.length;
+
+	for (let i = 1; i < n; i++) {
+		let top = stack.at(-1);
+        // 情况三
+		if (heights[top] < heights[i]) {
+			stack.push(i);
+		}
+        // 情况二
+		if (heights[top] === heights[i]) {
+			stack.pop(); // 这个可以加，可以不加，效果一样，思路不同
+			stack.push(i);
+		}
+        // 情况一
+		if (heights[top] > heights[i]) {
+			while (stack.length > 0 && heights[top] > heights[i]) {
+                // 栈顶元素出栈，并保存栈顶bar的索引
+				const h = heights[stack.pop()];
+				const left = stack.at(-1) ?? -1;
+				const w = i - left - 1;
                 // 计算面积，并取最大面积
-                maxArea = Math.max(maxArea, w * h);
-            }
-            stack.push(i);// 当前bar比栈顶bar高了，入栈
-        }
-    }
-    return maxArea;
+				maxArea = Math.max(maxArea, w * h);
+				top = stack.at(-1);
+			}
+			stack.push(i);
+		}
+	}
+	return maxArea;
 };
 
 //单调栈 简洁