#include <iostream>#include <cstdio>#include <cstring>#include <string>#include <algorithm>using namespace std;const int maxn=55;struct point{double x,y;} p[maxn];double cross(point c1,point b1,point a2){return (b1.x-c1.x)*(a2.y-c1.y)-(b1.y-c1.y)*(a2.x-c1.x);}bool cmp(point a,point b){point c;c.x=0;c.y=0;return cross(c,b,a)<0;}int main(){int n=0;while(scanf("%lf %lf",&p[n].x,&p[n].y)!=EOF)n++;sort(p+1,p+n, cmp);for(int i =0; i<n; i++)cout<<"("<<p[i].x<<","<<p[i].y<<")"<<endl;return 0;}
，可是旅行的彼时那刻我的心情一直是好的吗？
