leetcode_question_57 Insert Interval

时间:2021-09-10 23:21:16

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].

/**
* 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) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<Interval>::iterator itstart=intervals.begin();
for(; itstart!=intervals.end(); ++itstart)
if((*itstart).start <= newInterval.start && newInterval.start <= (*itstart).end)
break;
vector<Interval>::iterator itend=intervals.begin();
for(; itend!=intervals.end(); ++itend)
if((*itend).start <= newInterval.end && newInterval.end <= (*itend).end)
break;
if(itstart!=intervals.end() && itend!=intervals.end())
{
if(itstart != itend)
{
(*itstart).end = (*itend).end;
int tmp = (*itstart).end;
itstart++;
while(itstart != intervals.end())
if((*itstart).start <= tmp)
itstart = intervals.erase(itstart);
else break;
}
return intervals;
}else if(itstart==intervals.end() && itend!=intervals.end())
{
(*itend).start = newInterval.start;
int tmp1 = (*itend).start;
int tmp2 = (*itend).end;
itstart = intervals.begin();
while((*itstart).start != tmp1 && (*itstart).end != tmp2)
if((*itstart).start >= tmp1 && (*itstart).end <= tmp2)
itstart = intervals.erase(itstart);
else ++itstart;
return intervals;
}else if(itstart!=intervals.end() && itend==intervals.end())
{
(*itstart).end = newInterval.end;
int tmp = newInterval.end;
++itstart;
while(itstart != intervals.end())
if((*itstart).start < tmp)
itstart = intervals.erase(itstart);
else break;
return intervals;
}else{
vector<Interval>::iterator it=intervals.begin();
for(; it!=intervals.end(); ++it)
if((*it).start > newInterval.start)
break;
//--it;
vector<Interval>::iterator it1 = intervals.insert(it,newInterval);
while(it1 != intervals.end())
{
if((*it1).end < newInterval.end)
it1 = intervals.erase(it1);
else
it1++;
}
return intervals;
}
}
};