添加（0084.柱状图中最大的矩形.md）：增加typescript版本

Author: xiaofei-2020

problems/0084.柱状图中最大的矩形.md

@@ -486,5 +486,95 @@ var largestRectangleArea = function(heights) {
     return maxArea;
 };
 ```
+TypeScript：
+
+> 双指针法（会超时）：
+
+```typescript
+function largestRectangleArea(heights: number[]): number {
+    let resMax: number = 0;
+    for (let i = 0, length = heights.length; i < length; i++) {
+        // 左开右开
+        let left: number = i - 1,
+            right: number = i + 1;
+        while (left >= 0 && heights[left] >= heights[i]) {
+            left--;
+        }
+        while (right < length && heights[right] >= heights[i]) {
+            right++;
+        }
+        resMax = Math.max(resMax, heights[i] * (right - left - 1));
+    }
+    return resMax;
+};
+```
+
+> 动态规划预处理：
+
+```typescript
+function largestRectangleArea(heights: number[]): number {
+    const length: number = heights.length;
+    const leftHeightDp: number[] = [],
+        rightHeightDp: number[] = [];
+    leftHeightDp[0] = -1;
+    rightHeightDp[length - 1] = length;
+    for (let i = 1; i < length; i++) {
+        let j = i - 1;
+        while (j >= 0 && heights[i] <= heights[j]) {
+            j = leftHeightDp[j];
+        }
+        leftHeightDp[i] = j;
+    }
+    for (let i = length - 2; i >= 0; i--) {
+        let j = i + 1;
+        while (j < length && heights[i] <= heights[j]) {
+            j = rightHeightDp[j];
+        }
+        rightHeightDp[i] = j;
+    }
+    let resMax: number = 0;
+    for (let i = 0; i < length; i++) {
+        let area = heights[i] * (rightHeightDp[i] - leftHeightDp[i] - 1);
+        resMax = Math.max(resMax, area);
+    }
+    return resMax;
+};
+```
+
+> 单调栈：
+
+```typescript
+function largestRectangleArea(heights: number[]): number {
+    heights.push(0);
+    const length: number = heights.length;
+    // 栈底->栈顶：严格单调递增
+    const stack: number[] = [];
+    stack.push(0);
+    let resMax: number = 0;
+    for (let i = 1; i < length; i++) {
+        let top = stack[stack.length - 1];
+        if (heights[top] < heights[i]) {
+            stack.push(i);
+        } else if (heights[top] === heights[i]) {
+            stack.pop();
+            stack.push(i);
+        } else {
+            while (stack.length > 0 && heights[top] > heights[i]) {
+                let mid = stack.pop();
+                let left = stack.length > 0 ? stack[stack.length - 1] : -1;
+                let w = i - left - 1;
+                let h = heights[mid];
+                resMax = Math.max(resMax, w * h);
+                top = stack[stack.length - 1];
+            }
+            stack.push(i);
+        }
+    }
+    return resMax;
+};
+```
+
+
+
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