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用两条边平行且相等，判断平行四边形。 把所有边转换成向量。mulitest 记录每种向量的个数，在统计#include <bits/stdc++.h>#define maxn 100005#define INF 1e9using namespace std;typedef long long ll;struct Node{ Node(){ } Node(int a,

原题链接D. Magic Boxtime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputOne day Vasya was going ho

原题链接C. Peter and Snow Blowertime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputPeter got a new snow blo