kochcurve.cpp

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

using namespace std;

void snow(int x1, int y1, int x2, int y2, int it)
{
    float angle = 60 * M_PI / 180;
    int x3 = (2 * x1 + x2) / 3;
    int y3 = (2 * y1 + y2) / 3;
    int x4 = (x1 + 2 * x2) / 3;
    int y4 = (y1 + 2 * y2) / 3;
    int xx3 = x3 + (x4 - x3) * cos(angle) + (y4 - y3) * sin(angle);
    int yy3 = y3 - (x4 - x3) * sin(angle) + (y4 - y3) * cos(angle);

    if (it > 0)
    {
        snow(x1, y1, x3, y3, it - 1);
        snow(x3, y3, xx3, yy3, it - 1);
        snow(xx3, yy3, x4, y4, it - 1);
        snow(x4, y4, x2, y2, it - 1);
    }
    else
    {
        line(x1, y1, x3, y3);
        line(x3, y3, xx3, yy3);
        line(xx3, yy3, x4, y4);
        line(x4, y4, x2, y2);
    }
}

int main()
{
    int gd = DETECT, gm;
    initgraph(&gd, &gm, NULL);

    int x1 = 150, y1 = 100, x2 = 350, y2 = 100;

    snow(x1, y1, x2, y2, 2);
    snow(250, 350, 150, 100, 2);
    snow(350, 100, 250, 350, 2);

    getch();
    return 0;
}