Unique Elements

View as PDF
Submit solution
Points: 3 (partial)
Time limit: 5.0s
Memory limit: 64M
Author:
Xyene
Problem type

Given a list of N (1 \le N \le 30\,000) positive integers less than or equal to 10^9, print out how many distinct numbers exist.

Input Specification

The first line will contain the integer N. The next N lines will contain an element in the list.

Output Specification

One integer: the number of distinct elements in the given list.

Sample Input 1

2
1
2

Sample Output 1

2

Sample Input 2

4
1
2
2
5

Sample Output 2

3

Comments


  • 3
    echofox  commented on July 21, 2018, 8:22 p.m. ← edit 2

    this is so sad

    e


  • 0
    Oppenheimer  commented on Oct. 1, 2014, 5:31 p.m.

    You one-liners make me feel bad...


    • 0
      Xyene  commented on Oct. 1, 2014, 10:08 p.m.

      Hint: sets have very fast O(1) in checks, whereas lists have very slow O(n) in checks. Your solution will probably pass if you use a set, but you may have to combine your two for loops into one.


    • 2
      FatalEagle  commented on Oct. 1, 2014, 10:01 p.m.

      It appears that your solution doesn't have the intended complexity (the real testdata used to have N <= 20). As such, the limits have been increased and solutions have been rejudged :)