hical.js

// Your company built an in-house calendar tool called HiCal.
// You want to add a feature to see the times in a day when everyone is available.
// To do this, you’ll need to know when any team is having a meeting.
// In HiCal, a meeting is stored as a tuple of integers [start_time, end_time].
// These integers represent the number of 30-minute blocks past 9:00am.
// Writ a function that takes an array of meeting times and returns a condensed version.

function hiCal(times) {
  times = times.sort(function(a,b) {
    return a[0] - b[0];
  });
  
  var prevStart = times[0][0],
        prevEnd = times[0][1],
    mergedTimes = [];

  for (var i = 1; i < times.length; i++) {
    if (times[i][0] <= prevEnd) {
        prevEnd = times[i][1];
    } else {
        mergedTimes.push([prevStart, prevEnd]);
        prevStart = times[i][0];
        prevEnd = times[i][1];
    }
  }
  
  mergedTimes.push([prevStart, prevEnd]);
  return mergedTimes
}