LeetCode 84 Largest Rectangle in Histrogram (C++, Python)

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Given n non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.
For example,
Given height = [2,1,5,6,2,3],
return 10.

Solution C++


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class Solution {
public:
    int largestRectangleArea(vector<int>& height) {
        if (height.empty()) return 0;
        int size = height.size();
        int left[size];
        int right[size];
        for (int i = 0; i < size; ++i) {
            int j = i;
            while (j > 0 && height[i] <= height[j - 1]) {
                j = left[j - 1];
            }
            left[i] = j;
        }
        for (int i = size- 1; i >=0; --i) {
            int j = i;
            while (j < size- 1 && height[i] <= height[j + 1]) {
                j = right[j + 1];
            }
            right[i] = j;
        }
        int area = 0;
        for (int i = 0; i < size; ++i) {
            area = max(area, height[i] * (right[i] - left[i] + 1));
        }
        return area;
    }
};
Solution Python


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class Solution:
    # @param {integer[]} height
    # @return {integer}
    def largestRectangleArea(self, height):
        height.append(0)
        i = 0;
        increStack = []
        area = 0
        while i < len(height):
            if not increStack or height[i] > height[increStack[-1]]:
                increStack.append(i)
                i += 1
            else:
                tmp = height[increStack.pop()]
                area = max(area, tmp * ((i - increStack[-1] - 1) if (increStack) else i))
        return area

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