A14411. Array Differentiation
编程题
普及/提高-
知识点
题目描述
You are given a sequence of $n$ integers $a_1, \, a_2, \, \dots, \, a_n$ .
Does there exist a sequence of $n$ integers $b_1, \, b_2, \, \dots, \, b_n$ such that the following property holds?
- For each $1 \le i \le n$ , there exist two (not necessarily distinct) indices $j$ and $k$ ( $1 \le j, \, k \le n$ ) such that $a_i = b_j - b_k$ .
Does there exist a sequence of $n$ integers $b_1, \, b_2, \, \dots, \, b_n$ such that the following property holds?
- For each $1 \le i \le n$ , there exist two (not necessarily distinct) indices $j$ and $k$ ( $1 \le j, \, k \le n$ ) such that $a_i = b_j - b_k$ .
输入格式
The first line contains a single integer $t$ ( $1 \le t \le 20$ ) — the number of test cases. Then $t$ test cases follow.
The first line of each test case contains one integer $n$ ( $1 \le n \le 10$ ).
The second line of each test case contains the $n$ integers $a_1, \, \dots, \, a_n$ ( $-10^5 \le a_i \le 10^5$ ).
The first line of each test case contains one integer $n$ ( $1 \le n \le 10$ ).
The second line of each test case contains the $n$ integers $a_1, \, \dots, \, a_n$ ( $-10^5 \le a_i \le 10^5$ ).
输出格式
For each test case, output a line containing YES if a sequence $b_1, \, \dots, \, b_n$ satisfying the required property exists, and NO otherwise.
输入输出样例
输入 #1
5 5 4 -7 -1 5 10 1 0 3 1 10 100 4 -3 2 10 2 9 25 -171 250 174 152 242 100 -205 -258
输出 #1
YES YES NO YES YES
说明/提示
In the first test case, the sequence $b = [-9, \, 2, \, 1, \, 3, \, -2]$ satisfies the property. Indeed, the following holds:
- $a_1 = 4 = 2 - (-2) = b_2 - b_5$ ;
- $a_2 = -7 = -9 - (-2) = b_1 - b_5$ ;
- $a_3 = -1 = 1 - 2 = b_3 - b_2$ ;
- $a_4 = 5 = 3 - (-2) = b_4 - b_5$ ;
- $a_5 = 10 = 1 - (-9) = b_3 - b_1$ .
In the second test case, it is sufficient to choose $b = [0]$ , since $a_1 = 0 = 0 - 0 = b_1 - b_1$ .
In the third test case, it is possible to show that no sequence $b$ of length $3$ satisfies the property.
- $a_1 = 4 = 2 - (-2) = b_2 - b_5$ ;
- $a_2 = -7 = -9 - (-2) = b_1 - b_5$ ;
- $a_3 = -1 = 1 - 2 = b_3 - b_2$ ;
- $a_4 = 5 = 3 - (-2) = b_4 - b_5$ ;
- $a_5 = 10 = 1 - (-9) = b_3 - b_1$ .
In the second test case, it is sufficient to choose $b = [0]$ , since $a_1 = 0 = 0 - 0 = b_1 - b_1$ .
In the third test case, it is possible to show that no sequence $b$ of length $3$ satisfies the property.