習題5-2(uva-1594)

#include <iostream>
#include <vector>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include <algorithm>
#include <numeric>
#include <chrono>
#include <ctime>
#include <cmath>
#include <cctype>
#include <string>
#include <cstdio>
#include <iomanip>

#include <thread>
#include <mutex>
#include <condition_variable>
#include <functional>
#include <iterator>
using namespace std;
const int num = 131;
int arr[36],n, len;
unordered_set<unsigned int> mhash;

unsigned int GetHash() {
	unsigned int hash = 0;
	for (int i = 0; i < len; ++i) {
		hash = hash * num + arr[i];
	}
	return hash;
}
void GetNext() {
	int next = 0,base = abs(arr[0] - arr[1]);
	for (int i = 1; i < len; ++i) {
		next = (i + 1) % len;
		arr[i] = abs(arr[i] - arr[next]);
	}
	arr[0] = base;
}
int main()
{
	cin >> n;
	while (n--) {
		unsigned int hash = 0;
		mhash.clear();
		cin >> len;
		for (int i = 0; i < len; ++i) {
			cin >> arr[i];
		}
		while (true)
		{
			hash = GetHash();
			if(hash == 0 || mhash.count(hash)) break;
			mhash.insert(hash);
			GetNext();
		}
		if (hash == 0) cout << "ZERO" << endl;
		else cout << "LOOP" << endl;
	}
	return 0;
}