##### Short Problem Definition:

There are NN buildings in a certain two-dimensional landscape. Each building has a height given by hi,i∈[1,N]hi,i∈[1,N]. If you join KK adjacent buildings, they will form a solid rectangle of area K×min(hi,hi+1,…,hi+k−1)K×min(hi,hi+1,…,hi+k−1).

Given NN buildings, find the greatest such solid area formed by consecutive buildings.

##### Link

##### Complexity:

time complexity is `O(N)`

space complexity is `O(N)`

##### Execution:

Best explained on Geeks for Geeks.

##### Solution:

```
def computeLargestArea(hist, N):
stack = []
max_area = 0
idx = 0
while (idx < N):
if not stack or hist[stack[-1]] <= hist[idx]:
stack.append(idx)
idx += 1
else:
height_idx = stack.pop()
depth = idx
if stack:
depth = idx - stack[-1] - 1
area = hist[height_idx] * depth
max_area = max(area, max_area)
while stack:
height_idx = stack.pop()
depth = idx
if stack:
depth = idx - stack[-1] - 1
area = hist[height_idx] * depth
max_area = max(area, max_area)
return max_area
def main():
N = int(raw_input())
hist = map(int, raw_input().split())
print computeLargestArea(hist, N)
if __name__ == '__main__':
main()
```