191. Trapping Rain Water

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Example 1:

Input: height = [0,1,0,2,1,0,1,3,2,1,2,1]

Output: 6

Explanation: The elevation map represents various bar heights. Water fills the depressions. For instance, between heights 2 and 3, there's a depression of 1 unit at index 5 (height 0), trapping (min(2,3) - 0) = 2 units. Similarly for other spots, totaling 6 units.

Example 2:

Input: height = [4,2,0,3,2,5]

Output: 9

Explanation: Here, between 4 and 5, significant water is trapped. For example, at index 2 (height 0), 4 units are trapped (min(4,5)-0). At index 1 (height 2), 2 units are trapped (min(4,5)-2). Summing all such contributions results in 9 units.

Constraints:

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Time Complexity

o(n)

Space Complexity

o(1)

191. Trapping Rain Water

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Example 1:

Example 2:

Constraints:

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191. Trapping Rain Water

Understand Before Coding

Visualize This Problem

Draw Your Approach

Example 1:

Example 2:

Constraints:

Learn

Topics

Companies

Hint

Use Cases