FLOW004 - Editorial

Problem Link - First and Last Digit Practice Problem in 500 difficulty rating

Problem Statement:

Given an integer N . Write a program to obtain the sum of the first and last digits of this number.

Approach:

  • Extracting the Last Digit: The last digit of N can be found using the modulus operation: last_digit = N % 10.
  • Extracting the First Digit: To find the first digit, divide N by 10 repeatedly until N becomes less than 10. The remaining value is the first digit.
  • Calculating the Sum: Calculate the sum of the first and last digits and print the result for each test case.

Complexity:

  • Time Complexity: O(log N) represents the number of divisions needed to extract the first digit.
  • Space Complexity: O(1), as we are only using basic variables for calculations.