答案为Catalan数C(2k, k)/(k+1) #include <stdio.h> using namespace std; int k; int main() { scanf("%d", &k); long long ans = 1; for (int i = 1; i <= k; ++i) ans = ans * (k + k - i + 1) / i; printf("%I64d %d", ans / (k + 1), k +…
130. Circle time limit per test: 0.25 sec. memory limit per test: 4096 KB On a circle border there are 2k different points A1, A2, ..., A2k, located contiguously. These points connect k chords so that each of points A1, A2, ..., A2k is the end point…
用Python+turtle绘制佩琪: from turtle import * def nose(x,y):#鼻子 penup()#提起笔 goto(x,y)#定位 pendown()#落笔,开始画 setheading(-30)#将乌龟的方向设置为to_angle/为数字(0-东.90-北.180-西.270-南) begin_fill()#准备开始填充图形 a=0.4 for i in range(120): if 0<=i<30 or 60<=i<90: a=a+0.08…