题库练习 Running for Gold
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A14413 | Running for Gold

时间限制1s
内存限制256MB
通过 / 提交0/0

题目描述

The Olympic Games have just started and Federico is eager to watch the marathon race.

There will be $n$ athletes, numbered from $1$ to $n$ , competing in the marathon, and all of them have taken part in $5$ important marathons, numbered from $1$ to $5$ , in the past. For each $1\le i\le n$ and $1\le j\le 5$ , Federico remembers that athlete $i$ ranked $r_{i,j}$ -th in marathon $j$ (e.g., $r_{2,4}=3$ means that athlete $2$ was third in marathon $4$ ).

Federico considers athlete $x$ superior to athlete $y$ if athlete $x$ ranked better than athlete $y$ in at least $3$ past marathons, i.e., $r_{x,j}<r_{y,j}$ for at least $3$ distinct values of $j$ .

Federico believes that an athlete is likely to get the gold medal at the Olympics if he is superior to all other athletes.

Find any athlete who is likely to get the gold medal (that is, an athlete who is superior to all other athletes), or determine that there is no such athlete.

输入格式

The first line contains a single integer $t$ ( $1 \le t \le 1000$ ) — the number of test cases. Then $t$ test cases follow.

The first line of each test case contains a single integer $n$ ( $1\le n\le 50\,000$ ) — the number of athletes.

Then $n$ lines follow, each describing the ranking positions of one athlete.

The $i$ -th of these lines contains the $5$ integers $r_{i,1},\,r_{i,2},\,r_{i,3},\,r_{i,4},\, r_{i,5}$ ( $1\le r_{i,j}\le 50\,000$ ) — the ranking positions of athlete $i$ in the past $5$ marathons. It is guaranteed that, in each of the $5$ past marathons, the $n$ athletes have distinct ranking positions, i.e., for each $1\le j\le 5$ , the $n$ values $r_{1,j},\, r_{2, j},\, \dots,\, r_{n, j}$ are distinct.

It is guaranteed that the sum of $n$ over all test cases does not exceed $50\,000$ .

输出格式

For each test case, print a single integer — the number of an athlete who is likely to get the gold medal (that is, an athlete who is superior to all other athletes). If there are no such athletes, print $-1$ . If there is more than such one athlete, print any of them.

输入输出样例

输入 #1
4
1
50000 1 50000 50000 50000
3
10 10 20 30 30
20 20 30 10 10
30 30 10 20 20
3
1 1 1 1 1
2 2 2 2 2
3 3 3 3 3
6
9 5 3 7 1
7 4 1 6 8
5 6 7 3 2
6 7 8 8 6
4 2 2 4 5
8 3 6 9 4
输出 #1
1
-1
1
5
C++ 编辑器
输入
输出