题目描述
Problem Statement
Given is a number sequence of length N: p_1, ..., p_N.
For each i=1, 2, ..., N, find the minimum non-negative integer that is not equal to any of the numbers p_1, ..., p_i.
Input
Input is given from Standard Input in the following format:
N
p_1 ... p_N
Output
Print N lines in total.
The $i-th line (1 \leq i \leq N)$ should contain the minimum non-negative integer that is not equal to any of the numbers p_1, ..., p_i.
Constraints
- $1 \leq N \leq 200,000$
- $0 \leq p_i \leq 200,000$
- All values in input are integers.
Sample Input 1
4
1 1 0 2
Sample Output 1
0
0
2
3
- The minimum non-negative integer that is not equal to p_1=1 is 0.
- The minimum non-negative integer that is not equal to any of p_1=1, p_2=1 is 0.
- The minimum non-negative integer that is not equal to any of p_1=1, p_2=1, p_3=0 is 2.
- The minimum non-negative integer that is not equal to any of p_1=1, p_2=1, p_3=0, p_4=2 is 3.
Sample Input 2
10
5 4 3 2 1 0 7 7 6 6
Sample Output 2
0
0
0
0
0
6
6
6
8
8
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
4
1 1 0 2
样例输出
0
0
2
3