How a simple code can produce a Sierpinski triangle
Published on
Sometimes even a simple code like this can produce an unbelievable output:
<pre style="text-align: center; min-width: 700px;"><script>
let arr = [];
for (let i = 0; i < 32; ++i) {
arr = arr.map((_, i) => arr[i] !== arr[i - 1] ? '*' : ' ');
arr.push('*');
document.writeln(arr.join(' '));
}
</script></pre>
Output:
*
* *
* *
* * * *
* *
* * * *
* * * *
* * * * * * * *
* *
* * * *
* * * *
* * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
* *
* * * *
* * * *
* * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
The code puts one * in the first row, after that in the next 31 rows puts *
symbol only when it has exactly 1 adjacent * in the upper row, otherwise puts empty space ( ).
Who could think that it can produce a recursive triangle, i.e. a fractal!