Check out example codes for "histogram largest rectange in cpp". It will help you in understanding the concepts better.

Code Example 1

``````// C++ program to find maximum rectangular area in
// linear time
#include<bits/stdc++.h>
using namespace std;

// The main function to find the maximum rectangular
// area under given histogram with n bars
int getMaxArea(int hist[], int n)
{
// Create an empty stack. The stack holds indexes
// of hist[] array. The bars stored in stack are
// always in increasing order of their heights.
stack<int> s;

int max_area = 0; // Initialize max area
int tp;  // To store top of stack
int area_with_top; // To store area with top bar
// as the smallest bar

// Run through all bars of given histogram
int i = 0;
while (i < n)
{
// If this bar is higher than the bar on top
// stack, push it to stack
if (s.empty() || hist[s.top()] <= hist[i])
s.push(i++);

// If this bar is lower than top of stack,
// then calculate area of rectangle with stack
// top as the smallest (or minimum height) bar.
// 'i' is 'right index' for the top and element
// before top in stack is 'left index'
else
{
tp = s.top();  // store the top index
s.pop();  // pop the top

// Calculate the area with hist[tp] stack
// as smallest bar
area_with_top = hist[tp] * (s.empty() ? i :
i - s.top() - 1);

// update max area, if needed
if (max_area < area_with_top)
max_area = area_with_top;
}
}

// Now pop the remaining bars from stack and calculate
// area with every popped bar as the smallest bar
while (s.empty() == false)
{
tp = s.top();
s.pop();
area_with_top = hist[tp] * (s.empty() ? i :
i - s.top() - 1);

if (max_area < area_with_top)
max_area = area_with_top;
}

return max_area;
}

// Driver program to test above function
int main()
{
int hist[] = {6, 2, 5, 4, 5, 1, 6};
int n = sizeof(hist)/sizeof(hist);
cout << "Maximum area is " << getMaxArea(hist, n);
return 0;
}``````

Learn ReactJs, React Native from akashmittal.com