南邮 OJ 1089 Duplicate Removal

Duplicate Removal

时间限制(普通/Java) :  1000 MS/ 3000 MS          运行内存限制 : 65536 KByte
总提交 : 257            测试通过 : 154 

比赛描述

The company Al's Chocolate Mangos has a web site where visitors can guess how many chocolate covered mangos are in a virtual jar. Visitors type in a guess between 1 and 99 and then click on a "Submit" button. Unfortunately, the response time from the server is often long, and visitors get impatient and click "Submit" several times in a row. This generates many duplicate requests.
Your task is to write a program to assist the staff at ACM in filtering out these duplicate requests. 

输入

The input consists of a series of lines, one for each web session. The first integer on a line is N, 0 < N ≤ 25, which is the number of guesses on this line. These guesses are all between 1 and 99, inclusive. The value N = 0 indicates the end of all the input.

输出

For each input data set, output a single line with the guesses in the original order, but with consecutive duplicates removed. Conclude each output line with the dollar sign character '$'. Note that there is a single space between the last integer and the dollar sign.

样例输入

5 1 22 22 22 3
4 98 76 20 76
6 19 19 35 86 86 86
1 7
0

样例输出

1 22 3 $
98 76 20 76 $
19 35 86 $
7 $

题目来源

ACM Mid-Central Regional 2009

#include<stdio.h>
int main(){
	int N,a,last_a;
	while(scanf("%d",&N)&&N){
		last_a = -1;
		while(N--){
			scanf("%d",&a);
			if(a != last_a)
				printf("%d ",a);
			last_a = a;
		}
		printf("$\n");
	}
}