Skip to main content

Recursion - Interview Questions - Question 1

Recursion - Interview Questions - Question 1


If needed, you can read the Recursion Basics first.

Please describe the recursion concept to a 5 years old?

Suggested Answers:

One: Russian dolls. If you open it, then there is "the same" but "smaller" one, until you reach to the most inside one.

Two: Thinking about that you are sitting at the last row of a very large class room. The rows of seats have been defined as starting with the one most close to the front chalkboard (1, 2, 3, ...). The question to ask is which row you are sitting now. 

Your can count it from the first row until to your row; but a different way is that: "if the row number of the one before mine is x, then my row is (x + 1)". Then the same procedure can be run until reaching the first row, which can return 1 easily. Then it can be used to return the row numbers for all the rest rows (including yours).

Comments

Post a Comment

Popular posts from this blog

Brute Force - Question 2

2105. Watering Plants II Alice and Bob want to water n plants in their garden. The plants are arranged in a row and are labeled from 0 to n - 1 from left to right where the ith plant is located at x = i. Each plant needs a specific amount of water. Alice and Bob have a watering can each, initially full. They water the plants in the following way: Alice waters the plants in order from left to right, starting from the 0th plant. Bob waters the plants in order from right to left, starting from the (n - 1)th plant. They begin watering the plants simultaneously. It takes the same amount of time to water each plant regardless of how much water it needs. Alice/Bob must water the plant if they have enough in their can to fully water it. Otherwise, they first refill their can (instantaneously) then water the plant. In case both Alice and Bob reach the same plant, the one with more water currently in his/her watering can should water this plant. If they have the same amount of water, then Alice ...
Post a Comment
Read more

Sliding Window - Question 1

Leetcode 76. Minimum Window Substring Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string "". The testcases will be generated such that the answer is unique. A substring is a contiguous sequence of characters within the string. Constraints: m == s.length n == t.length 1 <= m, n <= 10^5 s and t consist of uppercase and lowercase English letters. Analysis: The first step to do is to count the letters in string t, since the relative order of chars does not matter. After the counting, we can use two pointers method on string s: starting with beginning of the string s, the second pointer can continue to move until the sub-string [i, j) has all the chars in t, where i the index of the first pointer, and j is the index of the second pointer. We are looking for the sub-string with the minimum leng...
Post a Comment
Read more