#P10413. [蓝桥杯 2023 国 A] 圆上的连线

    ID: 11931 远端评测题 1000ms 512MiB 尝试: 0 已通过: 0 难度: 5 上传者: 标签>数学2023提交答案Catalan 数蓝桥杯国赛

[蓝桥杯 2023 国 A] 圆上的连线

Problem Description

Given a circle with n=2023n = 2023 points on it, numbered from 11 to nn in order.

How many different ways are there to draw line segments connecting pairs of points such that no two segments intersect at all. Two solutions are considered different if the number of segments is different, or if there exists any point whose connected point has a different number in the other solution.

The answer may be very large. Please submit the answer modulo 20232023.

Input Format

This is an output-only fill-in-the-blank problem. You only need to compute the result and submit it. The result of this problem is an integer. When submitting, only fill in this integer; any extra content will cause you to receive no score.

Output Format

This is an output-only fill-in-the-blank problem. You only need to compute the result and submit it. The result of this problem is an integer. When submitting, only fill in this integer; any extra content will cause you to receive no score.

Hint

Translated by ChatGPT 5