/**
 * Time:      7  15   30
 * Distance:  9  40  200
 */
const example = [
    {
        time: 7,
        distance: 9
    },
    {
        time: 15,
        distance: 40
    },
    {
        time: 30,
        distance: 200
    }
]
/**
 * Time:        58     99     64     69
 * Distance:   478   2232   1019   1071
 */
const input = [
    {
        time: 58,
        distance: 478
    },
    {
        time: 99,
        distance: 2232
    },
    {
        time: 64,
        distance: 1019
    },
    {
        time: 69,
        distance: 1071
    }
]

function caculRangeOfBeatRecord(time: number, distance: number) {
    const mid = time / 2;
    const dist = Math.sqrt(Math.pow(time, 2) / 4 - distance);
    return {
        start: mid - dist, // include
        end: mid + dist, // exclude
    }
}

/**
 * count natrual numbers in the range. it could be real number.
 * @param {number} start
 * @param {number} end
 * @returns natrual numbers in the range
 */
function countRange(start: number, end: number) {
    return Math.ceil(end - 1) - Math.floor(start + 1) + 1
}

const res = input.map(e => {
    const range = caculRangeOfBeatRecord(e.time, e.distance);
    const count = countRange(range.start, range.end);
    console.log(range, count)
    return count;
}).reduce((a, b) => a * b, 1);

console.log(res);