LeetCode – Refresh – Insert Inverval

Similar to merge intervals. But this is easier than merge interval, because every side is kind of "sorted".

/**
 * Definition for an interval.
 * struct Interval {
 *     int start;
 *     int end;
 *     Interval() : start(0), end(0) {}
 *     Interval(int s, int e) : start(s), end(e) {}
 * };
 */
class Solution {
public:
    vector<Interval> insert(vector<Interval> &intervals, Interval newInterval) {
        vector<Interval> result;
        if (intervals.size() == 0) {
            result.push_back(newInterval);
            return result;
        }
        queue<int> left, right;
        int len = intervals.size();
        bool lf = true, rf = true;
        for (int i = 0; i < len; i++) {
            if (lf && newInterval.start < intervals[i].start) {
                left.push(newInterval.start);
                lf = false;
            }
            if (rf && newInterval.end < intervals[i].end) {
                right.push(newInterval.end);
                rf = false;
            }
            left.push(intervals[i].start);
            right.push(intervals[i].end);
        }
        if (lf) left.push(newInterval.start);
        if (rf) right.push(newInterval.end);
        while (!left.empty()) {
            int s = left.front(), e = right.front();
            left.pop(), right.pop();
            while (!left.empty()) {
                if (e >= left.front()) {
                    e = right.front();
                    left.pop(), right.pop();
                } else break;
            }
            result.push_back(Interval(s, e));
        }
        return result;
    }
};