Count Uncommon Elements
MediumPractice library · +20 XPhash mapcounting
Given a list of N integers, determine the count of integers that appear exactly once in the list.
Input
The first line contains an integer N (the number of elements). The second line contains N space-separated integers.
Output
Print a single integer: the count of elements that appear exactly once.
Constraints
1 <= N <= 200000; -10^9 <= integer value <= 10^9
Time limit 1 s (native code; slower languages get more)Memory 256 MB14 hidden tests
Example 1
Input
5 1 2 2 3 1
Output
1
Numbers 1 and 2 appear twice, number 3 appears once. Output is 1.
Example 2
Input
7 5 5 5 5 5 5 5
Output
0
The number 5 appears 7 times. No element appears exactly once. Output is 0.
Hints
# Read the input from stdin and print the answer.
import sys
def main():
data = sys.stdin.read().split()
# your code here
main()
Example 1 input
5 1 2 2 3 1
Example 2 input
7 5 5 5 5 5 5 5