SCU - 1997 Jolly Jumpers

SCU - 1997 Jolly Jumpers

A sequence of n > 0 integers is called a jolly jumper if the absolute values of the difference between successive elements take on all the values 1 through n-1. For instance,

1 4 2 3

is a jolly jumper, because the absolutes differences are 3, 2, and 1 respectively. The definition implies that any sequence of a single integer is a jolly jumper. You are to write a program to determine whether or not each of a number of sequences is a jolly jumper.

Input

Each line of input contains an integer n < 3000 followed by n integers representing the sequence.

Output

For each line of input, generate a line of output saying “Jolly” or “Not jolly”.

Sample Input

4 1 4 2 3
5 1 4 2 -1 6

Sample Output

Jolly
Not jolly

题意:
给一个长为n的序列，若序列任意相邻两个数差的绝对值为1,2,…,n-1之间的所有值，则输出“Jolly”，否则输出“Not jolly”。

思路：

1. 用数组a存储长为n的序列，数组b为任意两个数之间差的绝对值；
2. 将数组b从小到大排列（用sort函数）；
3. 判断数组b中的值是否与1,2,…,n-1一一对应，若对应，则输出“Jolly”，否则输出“Not jolly”。

代码如下：

#include 
#include 
#include 
using namespace std;
int main()
{
	int n;
	while(cin>>n)
	{	
		int i,a[3005],b[3005];
		for(i=0;i<n;++i)
		{
			cin>>a[i];
		}
		int j=0;
		for(i=0;i<n-1;++i)
		{
			b[j]=fabs(a[i]-a[i+1]);//存绝对值
			j++;
		}
		sort(b,b+j);
		int k=0;
		bool flag=true;
		for(i=1;i<n;++i)
		{
			if(b[k]!=i)
			{
				flag=false;
				break;
			}
			else
				k++;
		}
		if(flag)
			cout<<"Jolly";
		else
			cout<<"Not jolly";
		cout<<endl;
	}
	return 0;
}

测试链接.