这不就是“欢乐的跳”吗？

#include<set>
#include<iostream>
using namespace std;

int main(){
    int n;
    int nums[1010];
    cin>>n;
    for (int i=0;i<n;i++) cin>>nums[i];
    if (n == 1)
        printf("Jolly");
    else{
        set<int>diffs;
        set<int>required;
        for (int i=1;i<n;i++){
            diffs.insert(abs(nums[i] - nums[i-1]));
            required.insert(i);
        }
        if (diffs == required)
            printf("Jolly");
        else
            printf("Not jolly");
    }
    return 0;
}