[LeetCode] Insert Interval

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:
Given intervals [1,3],[6,9], insert and merge [2,5] in as [1,5],[6,9].

Example 2:
Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] in as [1,2],[3,10],[12,16].

This is because the new interval [4,9] overlaps with [3,5],[6,7],[8,10].

 1 /**
 2  * Definition for an interval.
 3  * struct Interval {
 4  *     int start;
 5  *     int end;
 6  *     Interval() : start(0), end(0) {}
 7  *     Interval(int s, int e) : start(s), end(e) {}
 8  * };
 9  */
10 class Solution {
11 private:
12     vector<Interval> ret;
13 public:
14     vector<Interval> insert(vector<Interval> &intervals, Interval newInterval) {
15         // Start typing your C/C++ solution below
16         // DO NOT write int main() function
17         ret.clear();
18         bool inserted = false;
19         if (intervals.size() == 0)
20         {
21             inserted = true;
22             ret.push_back(newInterval);
23         }
24 
25         int i = 0;
26         while (i < intervals.size())
27         {
28             if (ret.size() == 0)
29             {
30                 if (intervals[i].start < newInterval.start)
31                 {
32                     ret.push_back(intervals[i]);
33                     i++;
34                 }
35                 else
36                 {
37                     inserted = true;
38                     ret.push_back(newInterval);
39                 }
40             }
41             else
42             {
43                 int size = ret.size();
44                 if (inserted)
45                 {
46                     if (ret[size-1].start <= intervals[i].start && intervals[i].start <= ret[size-1].end)
47                         ret[size-1].end = max(ret[size-1].end, intervals[i].end);
48                     else
49                         ret.push_back(intervals[i]);
50                     i++;
51                 }
52                 else
53                 {
54                     if (newInterval.start < intervals[i].start)
55                     {
56                         inserted = true;
57                         if (ret[size-1].start <= newInterval.start && newInterval.start <= ret[size-1].end)
58                             ret[size-1].end = max(ret[size-1].end, newInterval.end);
59                         else
60                             ret.push_back(newInterval);
61                     }
62                     else
63                     {
64                         if (ret[size-1].start <= intervals[i].start && intervals[i].start <= ret[size-1].end)
65                             ret[size-1].end = max(ret[size-1].end, intervals[i].end);
66                         else
67                             ret.push_back(intervals[i]);
68                         i++;
69                     }
70                 }
71             }
72         }
73             
74         if (!inserted)
75         {
76             int size = ret.size();
77             if (ret[size-1].start <= newInterval.start && newInterval.start <= ret[size-1].end)
78                 ret[size-1].end = max(ret[size-1].end, newInterval.end);
79             else
80                 ret.push_back(newInterval);
81         }
82             
83         return ret;           
84     }
85 };
posted @ 2012-11-25 12:10  chkkch  阅读(1518)  评论(0)  编辑  收藏  举报