ZJUT OJ 1004

Jolly Jumpers 
Time Limit:1000MS  Memory Limit:1024K

Description:

A sequence of n （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 (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

code:

/*
本题需要注意理解题意，题中的意思是数列a中相邻两数的差必须囊括1到n-1。 
*/
#include <iostream>
#include <algorithm>
#include <math.h>
using namespace std;

int main()
{
    for(int n; cin >> n;) {
        int a[3000];
        for (int i = 0; i < n; i++) {
            cin >> a[i];
            if (i > 0)
                a[i - 1] = abs(a[i] - a[i - 1]);
        }
        sort(a, a + n - 1);
        bool flag = true;
        for (int i = 0; i < n - 1; i++) {
            if (a[i] != i + 1)
                flag = false;
        }
        cout << (flag ? "Jolly" : "Not jolly") << endl;
    }    
}