DSA problem solution: Climbing stairs

 

You are climbing a staircase. It takes n steps to reach the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

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DSA problem solution: Trapping Rain Water

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

Example 1:

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

Output: 6

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DSA Problem solution: Find Kth Largest Element in an Array using Heap in C#

Given an integer array nums and an integer k, return the kth largest element in the array.

Note that it is the kth largest element in the sorted order, not the kth distinct element.

Example 1:

Input: nums = [3,2,1,5,6,4], k = 2

Output: 5

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DSA Problem Solution: Binary Search

Given an array of integers nums which is sorted in ascending order, and an integer target, write a function to search target in nums. If target exists, then return its index. Otherwise, return -1.

Example 1:

Input: nums = [-6,1,3,5,9,11], target = 9

Output: 4

Explanation: 9 exists in nums and its index is 4

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DSA Problem Solution: Product of Array Except Self

Given an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements of nums except nums[i].

The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

Example 1:

Input: nums = [1,2,3,4]

Output: [24,12,8,6]

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