[draw sherpinski triangle in C language]

Shelpensky triangle

The serpinsky triangle is shown below ：

One 、 The code is as follows

#include <graphics.h>
#include
// Custom function , Draw the shelpinski triangle , Parameter is 3 Vertex coordinates
void sb(float x1, float y1, float x2, float y2, float x3, float y3)
{
if (abs(x1 - x2) + abs(x2 - x3) + abs(x3 - x1) + abs(y1 - y2) + abs(y2 - y3) +
abs(y3 - y1) < 20)
{
moveto(x1, y1);
lineto(x2, y2); // Draw triangle
lineto(x3, y3);
lineto(x1, y1);
}
else// Otherwise draw 3 A small serpinsky triangle
{
sb(x1, y1, (x1 + x2) / 2, (y1 + y2) / 2, (x1 + x3) / 2, (y1 + y3) / 2);
sb((x1 + x2) / 2, (y1 + y2) / 2, x2, y2, (x2 + x3) / 2, (y2 + y3) / 2);
sb((x1 + x3) / 2, (y1 + y3) / 2, (x2 + x3) / 2, (y2 + y3) / 2, x3, y3);
}
}

int main()
{
initgraph(1000, 750);
setbkcolor(WHITE);
setcolor(BLACK);
sb(500, 100, 150, 700, 900, 600); // Call custom functions , Draw a scherpinsky triangle
getch();
closegraph();
return 0;
}

summary

This code uses a recursive algorithm , Recursive algorithm for complex graphics , It can be drawn with very little code .