insert-interval.js

// Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).
//
// You may assume that the intervals were initially sorted according to their start times.
//
// Example 1:
//
//
// Input: intervals = [[1,3],[6,9]], newInterval = [2,5]
// Output: [[1,5],[6,9]]
//
//
// Example 2:
//
//
// Input: intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]
// Output: [[1,2],[3,10],[12,16]]
// Explanation: Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10].
//


/**
 * Definition for an interval.
 * function Interval(start, end) {
 *     this.start = start;
 *     this.end = end;
 * }
 */
/**
 * @param {Interval[]} intervals
 * @param {Interval} newInterval
 * @return {Interval[]}
 */
var insert = function(intervals, newInterval) {
    var result = [];
    var isInserted = false;
    var overlap = function(a, b) {
        return !(a.end < b.start || a.start > b.end);
    }
    for (var i = 0, len = intervals.length;i < len;++i) {
        if (! overlap(intervals[i], newInterval)) {
            if (!isInserted && intervals[i].start > newInterval.end) {
                result.push(newInterval);
                isInserted = true;
            }
            result.push(intervals[i]);
        } else {
            newInterval.start = Math.min(newInterval.start, intervals[i].start);
            newInterval.end = Math.max(newInterval.end, intervals[i].end);
        }
    }
    if (!isInserted) {
        result.push(newInterval);
    }
    return result;
};