算法精粹(algorithm-essentials)

感谢soulmachine@github提供内容
## Insert Interval


### 描述

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]`.


### 分析




### 代码

{% if book.java %}
```java
struct Interval {
int start;
int end;
Interval() : start(0), end(0) { }
Interval(int s, int e) : start(s), end(e) { }
};

// Insert Interval
// 时间复杂度O(n),空间复杂度O(1)
public class Solution {
public List insert(List intervals, Interval newInterval) {
for (int i = 0; i < intervals.size();) {
final Interval cur = intervals.get(i);
if (newInterval.end < cur.start) {
intervals.add(i, newInterval);
return intervals;
} else if (newInterval.start > cur.end) {
++i;
continue;
} else {
newInterval.start = Math.min(newInterval.start, cur.start);
newInterval.end = Math.max(newInterval.end, cur.end);
intervals.remove(i);
}
}
intervals.add(newInterval);
return intervals;
}
}
```
{% endif %}

{% if book.cpp %}
```cpp
// Insert Interval
// 时间复杂度O(n),空间复杂度O(1)
class Solution {
public:
vector insert(vector &intervals, Interval newInterval) {
vector::iterator it = intervals.begin();
while (it != intervals.end()) {
if (newInterval.end < it->start) {
intervals.insert(it, newInterval);
return intervals;
} else if (newInterval.start > it->end) {
it++;
continue;
} else {
newInterval.start = min(newInterval.start, it->start);
newInterval.end = max(newInterval.end, it->end);
it = intervals.erase(it);
}
}
intervals.insert(intervals.end(), newInterval);
return intervals;
}
};
```
{% endif %}


### 相关题目

* [Merge Intervals](merge-intervals.md)