[Leetcode] Largest Rectangle in histogram

Largest Rectangle in histogram

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.

Above is a histogram the where width of each bar is 1, given height = [2,1,5,6,2,3] .

The largest rectangle is shown in the shaded area, and which has an area = 10 unit.

For example,
Given height = [2,1,5,6,2,3] ,
Return 10 .

The general practice is to calculate the maximum area value for each point, and finally get the overall maximum, and the time complexity is O (n^2).

Using the nature of the stack, you can reduce the complexity of time to O (n). Refer to this blog post.

1 classSolution {2  Public:3     intLargestrectanglearea (vector<int>&height) {4         intresult=0;5Height.push_back (0);6stack<int>Mystack;7          for(intI=0; I)8         {9             if(Mystack.empty () | | height[mystack.top ()]<=Height[i])Ten             { One Mystack.push (i); A             } -             Else -             { the                 intindex =mystack.top (); - Mystack.pop (); -                 intArea = height[index]* (Mystack.empty ()? I: (I-mystack.top ()-1)); -result =Max (Result,area); +i--; -             } +         } A         returnresult; at     } -};

[Leetcode]largest Rectangle in histogram