### Lucky Turtlesnake

This #snake can sometimes win the game!

```Canvas.setpenopacity(1);
const divs = 40;
const extent = 100;
const step = 2*extent/divs;

const turtle = new Turtle();
let pixels = [...Array(divs)].map(_ => [...Array(divs)].map(_ => false));
turtle.penup();
let x = Math.floor(divs/4+Math.random()*divs/2);
let y = Math.floor(divs/4+Math.random()*divs/2);
let h = Math.round(Math.random()*4)*90;
let attempts = 0;
let optimism = 5;
let dirfn = turtle.left;
turtle.goto(x*step-extent/2, y*step-extent/2+step/2);
turtle.seth(h);

function pixel(opacity) {
turtle.goto(-extent+x*step+step/3, -extent+y*step+step/3);
turtle.seth(0);
turtle.forward(0.5);
turtle.right(90);
turtle.forward(0.5);
turtle.right(90);
turtle.pendown();
for (let i = turtle.y()-step; i < turtle.y()+step-2; i+=0.25/opacity) {
turtle.forward(step-1);
turtle.right(90);
turtle.forward(0.125/opacity);
turtle.right(90);
turtle.forward(step-1);
turtle.left(90);
turtle.forward(0.125/opacity);
turtle.left(90);
}
turtle.penup();
turtle.seth(h);
}

function attempt() {
h = Math.round(360+turtle.h())%360;
const oldx = x;
const oldy = y;
if (h === 270) {
if (x+1 < divs && pixels[x+1][y+1] === true && pixels[x+1][y] === false) {
h = (h + 90)%360;
x++;
}
else {
y--;
}
}
else if (h === 0) {
if (y+1 < divs && pixels[x-1][y+1] === true && pixels[x][y+1] === false) {
h = (h + 90)%360;
y++;
}
else {
x++;
}
}
else if (h === 90) {
if (x-1 >= 0 && pixels[x-1][y-1] === true && pixels[x-1][y] === false) {
h = (h + 90)%360;
x--;
}
else {
y++;
}
}
else if (h === 180) {
if (y-1 >= 0 && pixels[x-1][y-1] === true && pixels[x][y-1] === false) {
h = (h + 90)%360;
y--;
}
else {
x--;
}
}
turtle.seth(h);
if (x >= divs || x <= 0 || y >= divs || y <= 0) {
x = oldx;
y = oldy;
return false;
}
if (pixels[x][y]) {
x = oldx;
y = oldy;
return false;
}
return true;
}

function walk(i) {
attempts = 0;
dirfn = Math.random() ? turtle.left : turtle.right;
while (attempts < 3 && !attempt()) {
attempts++;
dirfn.call(turtle, 90);
if (optimism < 0) {
dirfn.call(turtle, 90);
}
if ((turtle.h()+180)%360 === h) {
dirfn.call(turtle, 90);
}
h = Math.round(360+turtle.h())%360;
}
if (attempts === 3) {
pixel(1);
return false;
} else {
pixels[x][y] = true;
pixel(i==0 ? 1 : 0.5);
optimism--;
if (optimism < 0) {
optimism = 5;
}
}
return true;
}
```