← 返回题目

题库练习 Ehab and Prefix MEXs

← 上一题下一题 →

A13520 | $Ehab and Prefix MEXs$

时间限制1s

内存限制256MB

通过 / 提交0/0

题目描述

Given an array $a$ of length $n$ , find another array, $b$ , of length $n$ such that: - for each $i$ $(1 \le i \le n)$ $MEX(\{b_1$ , $b_2$ , $\ldots$ , $b_i\})=a_i$ . The $MEX$ of a set of integers is the smallest non-negative integer that doesn't belong to this set. If such array doesn't exist, determine this.

输入格式

The first line contains an integer $n$ ( $1 \le n \le 10^5$ ) — the length of the array $a$ . The second line contains $n$ integers $a_1$ , $a_2$ , $\ldots$ , $a_n$ ( $0 \le a_i \le i$ ) — the elements of the array $a$ . It's guaranteed that $a_i \le a_{i+1}$ for $1\le i < n$ .

输出格式

If there's no such array, print a single line containing $-1$ . Otherwise, print a single line containing $n$ integers $b_1$ , $b_2$ , $\ldots$ , $b_n$ ( $0 \le b_i \le 10^6$ ) If there are multiple answers, print any.

输入输出样例

输入 #1

3
1 2 3

输出 #1

0 1 2

输入 #2

4
0 0 0 2

输出 #2

1 3 4 0

输入 #3

3
1 1 3

输出 #3

0 2 1

C++ 编辑器

输入

输出