Last Updated: 5 Jan, 2021
Remainder When Divided By 11
Easy
Asked in companies
You are given a number N. You need to find the remainder when N is divided by 11.
Note :
Number N may be very large.
Input format :
The first line contains an integer 'T' denoting the number of test cases to be run. The 'T' test cases follow.
The first line of each test case contains a single number 'N' in the form of a string.
Output Format :
For each test case, print an integer denoting the remainder when 'N' is divided by 11.
Constraints :
1 <= T <= 5
1 <= length of N <= 10 ^ 6
Time Limit: 1 sec
Approaches
- Since the number is very large we can not simply calculate N % 11.
- Now, any number say 256 % 11 can be calculated as (25*10 + 6)%11. Which in turn can be calculated as (( 25*10)%11+ 6)%11 or ( (25%11)*10 + 6)%11. Similarly 25%11 can be calculated as (2*10+5)%11. Therefore , 256 %11 can be finally calculated as ( ( (2*10 + 5)%11 )*10 + 6)%11.
- So, the idea is to store the number N in string Str.
- Take a variable Num, initialize it with 0.
- Now iterate character by character over the string and convert it into a digit, starting from 0th index.
- Multiply your current Num by 10 and add the current digit, say b, in it and then take it modulus with 11. So Num becomes Num = (Num*10 + b)%11.
- The final value of Num will be the required remainder.