6546: Laser
内存限制：512 MB
时间限制：1.000 S
评测方式：文本比较
命题人：
提交：8
解决：5
题目描述
There are n enemies on a two-dimensional plane, and the position of the i-th enemy is (xi ,yi )
You now have a laser weapon, which you can place on any grid (x,y)(x, y are real numbers) , and the weapon fires a powerful laser that for any real number k, enemies at coordinates (x+k,y),(x,y+k),(x+k,y+k),(x+k,y−k) will be destroyed.
You are now wondering if it is possible to destroy all enemies with only one laser weapon.
You now have a laser weapon, which you can place on any grid (x,y)(x, y are real numbers) , and the weapon fires a powerful laser that for any real number k, enemies at coordinates (x+k,y),(x,y+k),(x+k,y+k),(x+k,y−k) will be destroyed.
You are now wondering if it is possible to destroy all enemies with only one laser weapon.
输入
The first line of input is a positive integer T(T≤105) representing the number of data cases.
For each case, first line input a positive integer n to represent the position of the enemy.
Next n line, the i-th line inputs two integers xi ,yi (−108≤xi ,yi ≤108) represents the position of the i-th enemy.
The data guarantees that the sum of n for each test case does not exceed 500,000
For each case, first line input a positive integer n to represent the position of the enemy.
Next n line, the i-th line inputs two integers xi ,yi (−108≤xi ,yi ≤108) represents the position of the i-th enemy.
The data guarantees that the sum of n for each test case does not exceed 500,000
输出
For each cases, If all enemies can be destroyed with one laser weapon, output “YES“, otherwise output “NO“(not include quotation marks).
样例输入 复制
2
6
1 1
1 3
2 2
3 1
3 3
3 4
7
1 1
1 3
2 2
3 1
3 3
1 4
3 4样例输出 复制
YES
NO