Ducci Sequence UVA

习惯用结构体包一个数组，要存进set/map的话需要重载一下小于号，这样就能判重了

#include<bits/stdc++.h>
#include<stdio.h>
#include<algorithm>
#include<queue>
#include<string.h>
#include<iostream>
#include<math.h>
using namespace std;
#define ll long long
const int maxn=1e2+7;
const int inf=0x3f3f3f3f;
#define FOR(n) for(int i=1;i<=n;i++)
#define pb push_back

/******************************************************/
namespace fastIO{  
	#define BUF_SIZE 100000  
	#define OUT_SIZE 100000  
	#define ll long long  
	//fread->read  
	bool IOerror=0;  
	inline char nc(){  
		static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE;  
		if (p1==pend){  
			p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin);  
		if (pend==p1){IOerror=1;return -1;}  
		//{printf("IO error!
");system("pause");for (;;);exit(0);}  
	}  
	return *p1++;  
}  
inline bool blank(char ch){return ch==' '||ch=='
'||ch=='
'||ch=='	';}  
inline void read(int &x){  
	bool sign=0; char ch=nc(); x=0;  
	for (;blank(ch);ch=nc());  
	if (IOerror)return;  
	if (ch=='-')sign=1,ch=nc();  
	for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';  
	if (sign)x=-x;  
}  
inline void read(ll &x){  
	bool sign=0; char ch=nc(); x=0;  
	for (;blank(ch);ch=nc());  
	if (IOerror)return;  
	if (ch=='-')sign=1,ch=nc();  
	for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';  
	if (sign)x=-x;  
}  
inline void read(double &x){  
	bool sign=0; char ch=nc(); x=0;  
	for (;blank(ch);ch=nc());  
	if (IOerror)return;  
	if (ch=='-')sign=1,ch=nc();  
	for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';  
	if (ch=='.'){  
		double tmp=1; ch=nc();  
		for (;ch>='0'&&ch<='9';ch=nc())tmp/=10.0,x+=tmp*(ch-'0');  
	}  
	if (sign)x=-x;  
}  
inline void read(char *s){  
	char ch=nc();  
	for (;blank(ch);ch=nc());  
	if (IOerror)return;  
	for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch;  
	*s=0;  
}  
inline void read(char &c){  
	for (c=nc();blank(c);c=nc());  
	if (IOerror){c=-1;return;}  
} 
#undef OUT_SIZE  
#undef BUF_SIZE  
}; using namespace fastIO;
/*****************************************************/

struct NODE{
	int n;
	int arr[16];
	bool operator <(const NODE &b)const{
		for(int i=1;i<=n;i++){
			if(arr[i]!=b.arr[i])return arr[i]<b.arr[i];
		}
		return 0;
	}
};

//set<NODE>S;
map<NODE,bool>vis;

int main(){
	int T;
	//scanf("%d",&T);
	read(T);
	while(T--){
		vis.clear();
		NODE st;
		//scanf("%d",&st.n);
		read(st.n);
		for(int i=1;i<=st.n;i++){
			//scanf("%d",&st.arr[i]);
			read(st.arr[i]);
		}

		vis[st]=1;

		for(int p=1;p<=1111;p++){
			int tmp=st.arr[1];
			int flag=1;
			for(int i=1;i<st.n;i++){
				st.arr[i]=abs(st.arr[i+1]-st.arr[i]);
				if(st.arr[i]!=0)flag=0;
			}
			st.arr[st.n]=abs(st.arr[st.n]-tmp);
			if(st.arr[st.n]!=0)flag=0;

			if(flag){
				printf("ZERO
");
				break;
			}
			else if(!vis[st]){
				//S.insert(st);
				vis[st]=1;
			}else if(vis[st]){
				printf("LOOP
");
				break;
			}
		}

	}
}