Two Crystal balls failing for a custom test

[ppalmeida]

I wrote a manual test to investigate this algo better since I found it very interesting.

This test fails and returns -1

test("custom test", () => {
    const data = [
        false,
        false,
        false,
        false,
        false,
        false,
        false,
        false,
        false,
        true,
        true,
        true,
    ];
    expect(two_crystal_balls(data)).toEqual(9);
});

The way I've found to make it pass was considering the extra/last step like:

// Note the `j <= jumpAmount` instead of ` j < jumpAmount`
for (let j = 0; j <= jumpAmount && i < breaks.length; ++j, ++i) {
    if (breaks[i]) {
        return i;
    }
}

Keeping that <= condition still passes the other default tests from Prime. Removing it will break my test case. Am I right or am I missing something?

[ppalmeida]

Of course, this is the algo (exactly what it is in Primeagen video)

export default function two_crystal_balls(breaks: boolean[]): number {
    const jumpAmount = Math.floor(Math.sqrt(breaks.length));
    let i = jumpAmount;
    for (; i < breaks.length; i += jumpAmount) {
        if (breaks[i]) {
            break;
        }
    }

    i -= jumpAmount;

    for (let j = 0; j <= jumpAmount && i < breaks.length; ++j, ++i) {
        if (breaks[i]) {
            return i;
        }
    }

    return -1;
}

[JonathanD01]

The condition should be j <= jmpAmount as seen on the screenshot.