poj2265

转载于 2019-07-07 13:47:25 发布 · 79 阅读

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/james1207/p/3366157.html

斜坐标系，注意找规律。说明在代码里。

#include <iostream>
#include <math.h>

using namespace std;

#define eps 1e-6
#define zero(x) (((x)>0?(x):-(x))<eps)

int direct[6][2] = { { 0, 1 }, { -1, 1 }, { -1, 0 }, { 0, -1 }, { 1, -1 }, { 1, 0 } };//斜坐标系的六个方向

int main()
{
    int x;
    while (cin >> x)
    {
        double n = (sqrt(12 * x - 3)*1.0 - 3) / 6;
        int p = zero(n - ceil(n)) ? (int) n : ceil(n);
        int t = x - 3 * p * p + 3 * p - 1;
        int xcord, ycord;
        //x equals the n loops plus t.
        //cout << (int) p << ' ' << t << endl;
        xcord = p - 1; ycord = 0;
        while (1)
        {
            if (t == 0) goto L1;//t==0就可以撤出来了~
            xcord += direct[0][0], ycord += direct[0][1];//先向direct[0]走一步
            t--;
            if (t == 0) goto L1;
            for (int i = 1; i <= p - 1; i++)
            {
                xcord += direct[1][0], ycord += direct[1][1];//再向direct[1]走p-1步
                t--;
                if (t == 0) goto L1;
            }
            for (int i = 2; i <= 6; i++)
            {
                for (int j = 1; j <= p; j++)
                {
                    xcord += direct[i % 6][0], ycord += direct[i % 6][1];//然后向其他剩余的五个方向各走p步
                    t--;
                    if (t == 0) goto L1;
                }
            }
        }
    L1: cout << xcord << ' ' << ycord << endl;
    }
}

转载于:https://www.cnblogs.com/james1207/p/3366157.html