摘要：
叉乘，点乘，用结构体存cos^2 int n, ans = 1, X[N], Y[N]; struct node { double x,y; node(): node(0,0){} node(double x,double y):x(x),y(y){} bool operator < (const 阅读全文
摘要：
多校赛第二场B题 #include <bits/stdc++.h> #define ll long long #define lll unsigned long long #define pii pair<int, int> #define rep(i,a,b) for(ll i=a;i<=b;i+ 阅读全文