Grokking Data Structures & Algorithms for Coding Interviews
Ask Author
Back to course home

0% completed

Vote For New Content
Problem 1: Counting Elements (easy)
Table of Contents

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Problem Statement

Given a list of integers, determine the count of numbers for which there exists another number in the list that is greater by exactly one unit.

In other words, for each number x in the list, if x + 1 also exists in the list, then x is considered for the count.

Examples:

  1. Example 1:

    • Input: [4, 3, 1, 5, 6]
    • Expected Output: 3
    • Justification: The numbers 4, 3, and 5 have 5, 4, and 6 respectively in the list, which are greater by exactly one unit.

  2. Example 2:

    • Input: [7, 8, 9, 10]
    • Expected Output: 3
    • Justification: The numbers 7, 8, and 9 have 8, 9, and 10 respectively in the list, which are greater by exactly one unit.

  3. Example 3:

    • Input: [11, 13, 15, 16]
    • Expected Output: 1
    • Justification: Only the number 15 has 16 in the list, which is greater by exactly one unit.

Constraints:

  • 1 <= arr.length <= 1000
  • 0 <= arr[i] <= 1000

Try it yourself

Python3
Python3
. . . .

.....

.....

.....

Like the course? Get enrolled and start learning!

Table of Contents

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible