puzzle1.ts

let input: [boolean] = [
    true, true, true,
    false, false,
    true, true,
    false,
    true,
    false,
    true,
    false, false]

//Edge Trigger Model
function solve2(input: [boolean]): [number, number][] {
    let intervals: [number, number][] = new Array<[number, number]>();
    let start: number = 0, end: number = 0;
    input.push(input[0]);
    for (let idx = 1; idx < input.length; idx++) {
        //Are we at an edge?
        if (input[idx] != input[idx - 1]) {
            //Is the edge the start or end of a flippable interval?
            if (input[idx] != input[0]) {
                start = idx;
            } else {
                end = idx-1;
                intervals.push([start,end])
            }
        }
    }
    return intervals;
}

//State Machine Model
function solve(input: [boolean]): [number, number][] {
    let intervals: [number, number][] = new Array<[number, number]>();
    let start: number = 0, end: number = 0;


    for (let idx = 0; idx < input.length; idx++) {
        //State: Not in an interval
        //Trigger: Detected secondary data element.
        //Response: start an interval.
        if (start == 0 && input[idx] != input[0]) {
            start = idx;
        }
        //State: In an interval and should stop.
        //Trigger: Detected primary data element.
        //Response: end and record the interval.
        else if (start != 0 && input[idx] == input[0]) {
            end = idx - 1;
            intervals.push([start, end]);
            start == 0;
        }
    }
    if (start != 0) {
        intervals.push([start, input.length - 1]);
    }
    return intervals;
}
console.log(solve2(input));