Inventory

B. Inventory

time limit per test
1 second

memory limit per test
256 megabytes

input
standard input

output
standard output

Companies always have a lot of equipment, furniture and other things. All of them should be tracked. To do this, there is an inventory number assigned with each item. It is much easier to create a database by using those numbers and keep the track of everything.

During an audit, you were surprised to find out that the items are not numbered sequentially, and some items even share the same inventory number! There is an urgent need to fix it. You have chosen to make the numbers of the items sequential, starting with 1.
Changing a number is quite a time-consuming process, and you would like to make maximum use of the current numbering.

You have been given information on current inventory numbers for n items in the company. Renumber items so that their inventory numbers
form a permutation of numbers from 1 to n by
changing the number of as few items as possible. Let us remind you that a set ofn numbers forms a permutation if
all the numbers are in the range from 1 to n,
and no two numbers are equal.

Input

The first line contains a single integer n — the number of items (1 ≤ n ≤ 105).

The second line contains n numbers a1, a2, ..., an (1 ≤ ai ≤ 105) —
the initial inventory numbers of the items.

Output

Print n numbers — the final inventory numbers of the items in the order they occur in the input. If there are multiple possible answers,
you may print any of them.

Sample test(s)

input

3
1 3 2

output

1 3 2

input

4
2 2 3 3

output

2 1 3 4

input

1
2

output

1

Note

In the first test the numeration is already a permutation, so there is no need to change anything.

In the second test there are two pairs of equal numbers, in each pair you need to replace one number.

In the third test you need to replace 2 by 1,
as the numbering should start from one.

思路：

     这是一道模拟题，相当于给你从1-n个数去从新写出这1-n个数的序列。如果输入的数符合1-n就不改变他的位置，否则改变他。记录1-n未使用的数，而且从小到大记录。

AC代码：

     #include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
int a[100100],f[100100],t[100100];
int main()
{
//freopen("input.txt","r",stdin);
int n,i,k;
while(~scanf("%d",&n))
{
memset(f,0,sizeof(f));
for(i=1;i<=n;++i){
scanf("%d",&a[i]),f[a[i]]++;
if(a[i]>n)f[a[i]]=0;
}
if(n==1){printf("1\n");continue;}
for(i=1,k=0;i<=n;++i)
if(!f[i])t[k++]=i;
for(i=1,k=0;i<=n;++i)
{
if(!f[a[i]])printf("%d ",t[k++]);
else printf("%d ",a[i]),f[a[i]]=0;
}
printf("\n");
}
return 0;
}