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* Add rain-terraces (trapping rain water) algorithm * Fixed linting errors * Fixed linting errors
1.0 KiB
1.0 KiB
Rain Terraces (Trapping Rain Water) Problem
Given an array of non-negative integers representing terraces in an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.
Examples
Example #1
Input: arr[] = [2, 0, 2]
Output: 2
Structure is like below
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We can trap 2 units of water in the middle gap.
Example #2
Input: arr[] = [3, 0, 0, 2, 0, 4]
Output: 10
Structure is like below
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We can trap "3*2 units" of water between 3 an 2,
"1 unit" on top of bar 2 and "3 units" between 2
and 4. See below diagram also.
Example #3
Input: arr[] = [0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1]
Output: 6
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Trap "1 unit" between first 1 and 2, "4 units" between
first 2 and 3 and "1 unit" between second last 1 and last 2