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A14599 | Groups

时间限制1s
内存限制256MB
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题目描述

$n$ students attended the first meeting of the Berland SU programming course ( $n$ is even). All students will be divided into two groups. Each group will be attending exactly one lesson each week during one of the five working days (Monday, Tuesday, Wednesday, Thursday and Friday), and the days chosen for the groups must be different. Furthermore, both groups should contain the same number of students.

Each student has filled a survey in which they told which days of the week are convenient for them to attend a lesson, and which are not.

Your task is to determine if it is possible to choose two different week days to schedule the lessons for the group (the first group will attend the lesson on the first chosen day, the second group will attend the lesson on the second chosen day), and divide the students into two groups, so the groups have equal sizes, and for each student, the chosen lesson day for their group is convenient.

输入格式

The first line contains a single integer $t$ ( $1 \le t \le 10^4$ ) — the number of testcases.

Then the descriptions of $t$ testcases follow.

The first line of each testcase contains one integer $n$ ( $2 \le n \le 1\,000$ ) — the number of students.

The $i$ -th of the next $n$ lines contains $5$ integers, each of them is $0$ or $1$ . If the $j$ -th integer is $1$ , then the $i$ -th student can attend the lessons on the $j$ -th day of the week. If the $j$ -th integer is $0$ , then the $i$ -th student cannot attend the lessons on the $j$ -th day of the week.

Additional constraints on the input: for each student, at least one of the days of the week is convenient, the total number of students over all testcases doesn't exceed $10^5$ .

输出格式

For each testcase print an answer. If it's possible to divide the students into two groups of equal sizes and choose different days for the groups so each student can attend the lesson in the chosen day of their group, print "YES" (without quotes). Otherwise, print "NO" (without quotes).

输入输出样例

输入 #1
2
4
1 0 0 1 0
0 1 0 0 1
0 0 0 1 0
0 1 0 1 0
2
0 0 0 1 0
0 0 0 1 0
输出 #1
YES
NO
C++ 编辑器
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