Challenge 130
Table of Contents
Task 1 - Odd Number
You are given an array of positive integers, such that all the numbers appear even number of times except one number.
Write a script to find that integer.
Examples:
Input: @N = (2, 5, 4, 4, 5, 5, 2) Output: 5 as it appears 3 times in the array where as all other numbers 2 and 4 appears exactly twice. Input: @N = (1, 2, 3, 4, 3, 2, 1, 4, 4) Output: 4
Raku
- Program: raku/ch-1.raku
@nums holds the input and %seen is True if it's seen odd number of
times. We loop over @nums and invert the value of that number in %seen.
my Bool %seen; %seen{$_} = !%seen{$_} for @nums; put %seen.grep(*.value).map(*.key);