HDU 5533Dancing Stars on Me 基础几何

标签：str   date   sky   长度   c++   without   nat   let   math   

Problem Description

题意：问你是不是正多边形。

思路：瞎暴力XD。直接存所有点间连线的边长，偶数多边形长度一样的肯定有n/2个和n个，奇数多边形相同边长的一定是n啦。

/** @Date    : 2016-12-10-22.55
  * @Author  : Lweleth (SoungEarlf@gmail.com)
  * @Link    : https://github.com/
  * @Version :
  */
//#include <stdio.h>
//#include <iostream>
//#include <string.h>
//#include <algorithm>
//#include <utility>
//#include <vector>
//#include <map>
//#include <set>
//#include <string>
//#include <stack>
//#include <queue>
#include<bits/stdc++.h>
#define LL long long
#define PII pair<int ,int>
#define MP(x, y) make_pair((x),(y))
#define fi first
#define se second
#define PB(x) push_back((x))
#define MMG(x) memset((x), -1,sizeof(x))
#define MMF(x) memset((x),0,sizeof(x))
#define MMI(x) memset((x), INF, sizeof(x))
using namespace std;

const int INF = 0x3f3f3f3f;
const int N = 1e5+20;
const double eps = 1e-8;

struct yuu
{
    double x; double y;
    bool operator == (const yuu &a) const
    {
        return (a.x == this->x) && (a.y == this->y);
    }
}s[110], t[N];

int cmp(yuu a, yuu b)
{
    if(a.x != b.x)
        return a.x > b.x;
    return a.y > b.y;
}
map<double , int>q;
int main()
{
    int T;
    scanf("%d", &T);
    while(T--)
    {
        int n;
        scanf("%d", &n);
        q.clear();
        for(int i = 1; i <= n; i++)
            scanf("%lf%lf", &s[i].x, &s[i].y);

        int cnt = 0;
        for(int i = 1; i <= n; i++)
        {
            for(int j = i + 1; j <= n; j++)
            {
                double mx = fabs(s[i].x - s[j].x);
                double my = fabs(s[i].y - s[j].y);
                double len = mx * mx + my * my;
                q[len]++;
            }
        }
        int flag = 0;
        for(auto i = q.begin(); i != q.end(); i++)
        {
            if(n & 1 && i->second != n)
            {
                flag = 1;
                break;
            }
            else if(n % 2 == 0)
            {
                if(i->second != n / 2 && i->second != n)
                {
                    flag = 1;
                    break;
                }
            }
        }
        if(flag)
            printf("NO\n");
        else printf("YES\n");


    }
    return 0;
}

HDU 5533Dancing Stars on Me 基础几何

标签：str   date   sky   长度   c++   without   nat   let   math   

原文地址：http://www.cnblogs.com/Yumesenya/p/6158720.html