luogu#P16360. [BalticOI 2026] Distances

    ID: 16539 远端评测题 1000ms 512MiB 尝试: 0 已通过: 0 难度: 7 上传者: 标签>Special JudgeBalticOI(波罗的海)2026

[BalticOI 2026] Distances

Problem Description

You are given integers nn and kk. Your goal is to pick nn distinct integer points on the xyxy-plane such that for exactly kk pairs of points, the Euclidean distance between the points is an integer. Recall that the Euclidean distance between points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is

(x1x2)2+(y1y2)2.\sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}.

It can be shown that a solution always exists under the constraints of this task.

Input Format

The only line contains two integers, nn and kk.

Output Format

Print nn lines with the iith line containing two integers: the xx and yy coordinates of the iith point. The absolute value of every coordinate must be at most 10910^9.

If there are multiple solutions, you can print any of them.

3 2
1 1
1 2
2 2

Hint

Explanation

The Euclidean distance between (1,1)(1, 1) and (1,2)(1, 2) is 11. The distance between (1,2)(1, 2) and (2,2)(2, 2) is also 11. However, the distance between (1,1)(1, 1) and (2,2)(2, 2) is 2\sqrt 2, which is not an integer.

Constraints

  • 1n1001 \le n \le 100
  • 0kn(n1)/20 \le k \le n(n - 1) / 2

Scoring

Subtask Constraints Points
1 n4n \le 4 1111
2 k=n(n1)/2k = n(n-1)/2 44
3 k=0k = 0 66
4 knk \le n 1919
5 kn(n1)/8k \le n(n-1) / 8 2222
6 No additional constraints 3838