HISTOGRA  Largest Rectangle in a Histogram
A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal widths but may have different heights. For example, the figure on the left shows the histogram that consists of rectangles with the heights 2, 1, 4, 5, 1, 3, 3, measured in units where 1 is the width of the rectangles:
Usually, histograms are used to represent discrete distributions, e.g., the frequencies of characters in texts. Note that the order of the rectangles, i.e., their heights, is important. Calculate the area of the largest rectangle in a histogram that is aligned at the common base line, too. The figure on the right shows the largest aligned rectangle for the depicted histogram.
Input Specification
The input contains several test cases.
Each test case describes a histogram and starts with an integer n
, denoting the number of rectangles it is composed of.
You may assume that 1 <= n <= 100000
.
Then follow n
integers h_{1}, ..., h_{n}
, where 0 <= h_{i} <= 1000000000
.
These numbers denote the heights of the rectangles of the histogram in lefttoright order.
The width of each rectangle is 1
.
A zero follows the input for the last test case.
Output Specification
For each test case output on a single line the area of the largest rectangle in the specified histogram. Remember that this rectangle must be aligned at the common base line.
Sample Input
7 2 1 4 5 1 3 3 4 1000 1000 1000 1000 0
Sample Output
8 4000
hide comments
stones:
20190416 23:44:00
It can also be done using Union and Find in O(nlogn). 

Jumpy:
20190331 19:31:54
I was playing with values in stack, turned out it is dependent on index.


mayankg20:
20190127 18:20:13
@dkg...Same here


dkg335:
20190117 08:34:19
I 'am getting wrong answer , I've used stacks and also used long long int . 

aman786:
20190113 14:23:52
@kkislay20 use long long int


frost_:
20190103 16:48:26
Last edit: 20190103 17:00:45 

sonuexpc:
20181231 07:27:45
use long long int....cost me 2 WA... :( 

a1b3c7d9:
20181209 06:16:03
leave a name 

shubham_04_04:
20180923 06:58:48
Runtime error. Java. even using long. :( 

adarshtadwai:
20180828 13:21:55
https://www.hackerrank.com/challenges/largestrectangle/editorial

Added by:  Wanderley GuimarÄƒes 
Date:  20070921 
Time limit:  0.800s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO 
Resource:  University of Ulm Local Contest 2003 