poj 2575 Jolly Jumpers

//没有认真读题，WA了两次，因为他们的差值的顺序不一定需要按升序或者降序排列的！具体可以用下面的数据进行测试！
#include<iostream>
#include<cstring>
#include<cmath>
using namespace std;

int dif[3000];

int main(){
int n;
while(cin >> n){
memset(dif,0,sizeof(dif));
int pre,current;
cin >> pre;
int i;
for(i = 1; i < n; i++){
cin >> current;
int abs_dif = abs(current - pre);
dif[abs_dif] = 1;
pre = current;
}

for(i = 1; i < n; i++){
if(dif[i] == 0)
break;
}

if(i == n)
cout << "Jolly" << endl;
else
cout << "Not jolly" << endl;
}
}
/*
4 6 3 2 0
1 2
2 2 2
3 1 2 3
3 3 2 1
4 4 4 4 4
*/