84. Largest Rectangle in Histogram LeetCode Solution
In this guide, you will get 84. Largest Rectangle in Histogram LeetCode Solution with the best time and space complexity. The solution to Largest Rectangle in Histogram problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.
Problem Statement of Largest Rectangle in Histogram
Given an array of integers heights representing the histogram’s bar height where the width of each bar is 1, return the area of the largest rectangle in the histogram.
Example 1:
Input: heights = [2,1,5,6,2,3]
Output: 10
Explanation: The above is a histogram where width of each bar is 1.
The largest rectangle is shown in the red area, which has an area = 10 units.
Example 2:
Input: heights = [2,4]
Output: 4
Constraints:
1 <= heights.length <= 105
0 <= heights[i] <= 104
Complexity Analysis
Time Complexity: O(n)
Space Complexity: O(n)
84. Largest Rectangle in Histogram LeetCode Solution in C++
class Solution {
public:
int largestRectangleArea(vector<int>& heights) {
int ans = 0;
stack<int> stack;
for (int i = 0; i <= heights.size(); ++i) {
while (!stack.empty() &&
(i == heights.size() || heights[stack.top()] > heights[i])) {
const int h = heights[stack.top()];
stack.pop();
const int w = stack.empty() ? i : i - stack.top() - 1;
ans = max(ans, h * w);
}
stack.push(i);
}
return ans;
}
}; /* code provided by PROGIEZ */
84. Largest Rectangle in Histogram LeetCode Solution in Java
class Solution {
public int largestRectangleArea(int[] heights) {
int ans = 0;
Deque<Integer> stack = new ArrayDeque<>();
for (int i = 0; i <= heights.length; ++i) {
while (!stack.isEmpty() && (i == heights.length || heights[stack.peek()] > heights[i])) {
final int h = heights[stack.pop()];
final int w = stack.isEmpty() ? i : i - stack.peek() - 1;
ans = Math.max(ans, h * w);
}
stack.push(i);
}
return ans;
}
} // code provided by PROGIEZ
84. Largest Rectangle in Histogram LeetCode Solution in Python
class Solution:
def largestRectangleArea(self, heights: list[int]) -> int:
ans = 0
stack = []
for i in range(len(heights) + 1):
while stack and (i == len(heights) or heights[stack[-1]] > heights[i]):
h = heights[stack.pop()]
w = i - stack[-1] - 1 if stack else i
ans = max(ans, h * w)
stack.append(i)
return ans # code by PROGIEZ
