Data Structure Interview Questions with Solutions

Question: Given two Strings S and T, return true if they equal when both are typed out any "#" will be treated as backspace. input - S -> ab#c, T -> az#c output - True Constraints need to ask because solution may change according to given constraints Question: What happens when 2 or multiple "#" appear besides each other? Answer: Delete same number of values before 1st "#". Ex- ab## -> "" Question: What happen to "#" when there is no character to remove? Answer: It deletes nothing. Ex- a###b -> "b" Question: Are two empty Strings equals each other? Answer: Ex- S -> a#b#c#, T -> c#. Both returns empty string and output will be true. Question: Does case sensitivity matters? Answer: Yes. Ex- A is different from a. S -> ab#c, T -> Az#c. Output - False Solution using JAVA language. BruteForce Approach - This is simple approach, We are using JAVA Stack here,...

Question: Given an array of integers representing an elevation map (bar chart) where width of each bar is one, return how much rain water can be trapped in empty space. input [0,1,0,2,1,0,3,1,0,1,2] output 8 Constraints need to ask because solution may change according to given constraints Question: Sides of graph can be count as wall? Answer: No Question: Will there be negative integers? Answer: No Question: What will be output for empty array? Answer: 0 Question: What will be output when only 1 value in array? Answer: 0 Question: What will be output when input array like [3,4,3]? Answer: 0, no empty space to store water because walls cannot be used and water also fells from right side. Note: Max water can go to the mark is minimum height of bar between 2 bars and if there is a small bar present in between it will reduce the water quantity as shown in above image wit...

Question: Given an array of positive numbers where each number represent the height of a vertical line on a chart. Find two lines which together with the x-axis forms a container that would hold greatest amount of water. what will be the output which is max area of container formed by vertical lines. input [8, 2, 1, 5, 6, 9] output 40 Constraints need to ask because solution may change according to given constraints Question: Does the thickness of lines affect the are? Answer: No Question: Sides of graph can be count as wall? Answer: No Question: Does a higher line inside our container affect our area? Answer: No Question: What will be output for empty array? Answer: 0 Question: What will be output when only 1 value in array? Answer: 0 ...

Question: Find a pair of index from given array where sum of numbers present at those indices is equal to given target number? input [4,2,5,8,9,6] target 7 output [1,2] Constraints need to ask because solution may change according to given constraints Question: If the given array only contains positive numbers or negative can be present? Answer: Only Positive numbers. Question: What would be output, If target number is not sum of any pair present in array? Answer: null Question: What will be output if only one integer present in given array, because question asked for pair of numbers? Answer: null Question: What is the output when given array is empty? Answer: null Question: Is there any duplicate number present in array? Answer: No Question: If multiple pair can have target sum, what will be output? Answer: First pair you get.