Codeforces Round #373 (Div. 2) A. Vitya in the Countryside 水题

A. Vitya in the Countryside time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output

Every summer Vitya comes to visit his grandmother in the countryside. This summer, he got a huge wart. Every grandma knows that one should treat warts when the moon goes down. Thus, Vitya has to catch the moment when the moon is down.

Moon cycle lasts 30 days. The size of the visible part of the moon (in Vitya's units) for each day is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and then cycle repeats, thus after the second 1 again goes 0.

As there is no internet in the countryside, Vitya has been watching the moon for n consecutive days and for each of these days he wrote down the size of the visible part of the moon. Help him find out whether the moon will be up or down next day, or this cannot be determined by the data he has.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 92) — the number of consecutive days Vitya was watching the size of the visible part of the moon.

The second line contains n integers ai (0 ≤ ai ≤ 15) — Vitya's records.

It's guaranteed that the input data is consistent.

Output

If Vitya can be sure that the size of visible part of the moon on day n + 1 will be less than the size of the visible part on day n, then print "DOWN" at the only line of the output. If he might be sure that the size of the visible part will increase, then print "UP". If it's impossible to determine what exactly will happen with the moon, print -1.

Examples input 5 3 4 5 6 7 output UP input 7 12 13 14 15 14 13 12 output DOWN input 1 8 output -1 Note

In the first sample, the size of the moon on the next day will be equal to 8, thus the answer is "UP".

In the second sample, the size of the moon on the next day will be 11, thus the answer is "DOWN".

In the third sample, there is no way to determine whether the size of the moon on the next day will be 7 or 9, thus the answer is -1.

Source

Codeforces Round #373 (Div. 2)

My Solution

水题

刚开始对于n == 1的时候直接来了个 - 1；

然后其它地方 对于 0 必增， 15 必减， 否则看趋势。 忘了去把 n == 1 的时候也对这 0、15 特殊判断下了，所以被hack了， 然后改对，尴尬，幸好没有锁。

#include <iostream> #include <cstdio> using namespace std; typedef long long LL; const int maxn = 1e5 + 8; int sz[maxn]; int main() { #ifdef LOCAL freopen("a.txt", "r", stdin); //freopen("a.out", "w", stdout); int T = 4; while(T--){ #endif // LOCAL ios::sync_with_stdio(false); cin.tie(0); LL n; cin >> n; for(int i = 0; i < n; i++){ cin >> sz[i]; } if(n == 1){ if(sz[n-1] == 15) cout << "DOWN" << endl; else if(sz[n-1] == 0) cout << "UP" << endl; else cout << -1 << endl; } else{ if(sz[n - 1] > sz[n - 2]){ if(sz[n-1] == 15) cout << "DOWN" << endl; else cout << "UP" << endl; } else{ if(sz[n-1] == 0) cout << "UP" << endl; else cout << "DOWN" << endl; } } #ifdef LOCAL cout << endl; } #endif // LOCAL return 0; }

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