Unique Elements

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Points: 3 (partial)

Time limit: 5.0s

Memory limit: 64M

Author:

Xyene

Problem type

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

Input Specification

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

Output Specification

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

Sample Input 1

Copy

2
1
2

Sample Output 1

Copy

Sample Input 2

Copy

Sample Output 2

Copy

Comments

4

echofox commented on July 22, 2018, 12:22 a.m. ← edit 3 →

this is so sad

4

Oppenheimer commented on Oct. 1, 2014, 9:31 p.m.

You one-liners make me feel bad...

2

Xyene commented on Oct. 2, 2014, 2:08 a.m. ← edited →

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