/**
 * @param {number[][]} intervals
 * @return {number}
 */
var minMeetingRooms = function(intervals) {
    if (intervals.length < 1) return 0

    const startTimes = []
    const endTimes = []

    for (let i = 0; i<intervals.length; i++) {
        startTimes[i] = intervals[i][0]
        endTimes[i] = intervals[i][1]
    }

    startTimes.sort((a, b) => a-b)
    endTimes.sort((a, b) => a-b)

    let startPtr = 0
    let endPtr = 0
    let rooms = 0

    for (let i=0; i<intervals.length; i++) {
        if (startTimes[i] >= endTimes[endPtr]) {
            endPtr++
        } else {
            rooms++
        }
    }

    return rooms
};