题目
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.
238.jpg
For example,
Given heights = [2,1,5,6,2,3],
return 10.
解题之法
class Solution {
public:
int largestRectangleArea(vector<int> &height) {
int res = 0;
for (int i = 0; i < height.size(); ++i) {
if (i + 1 < height.size() && height[i] <= height[i + 1]) {
continue;
}
int minH = height[i];
for (int j = i; j >= 0; --j) {
minH = min(minH, height[j]);
int area = minH * (i - j + 1);
res = max(res, area);
}
}
return res;
}
};
分析
这道题可以用一种巧妙的方法：遍历数组，每找到一个局部峰值，然后向前遍历所有的值，算出共同的矩形面积，每次对比保留最大值。
