摘要:
http://acm.hdu.edu.cn/showproblem.php?pid=2080先用向量求出cosx,再用公式arcos(cosx)求得答案,,,,View Code 1 #include <stdio.h> 2 3 4 #include <stdlib.h> 5 6 #include <math.h> 7 8 #define PI 3.141592653 9 10 int main()11 12 {13 14 int n;15 16 double x1,x2,y1,y2,m,t;17 18 scanf("%d",&n 阅读全文