给出若干闭合区间, 合并所有重叠的部分.
样例
给出的区间列表 => 合并后的区间列表:
[[[1, 3], [1, 6],
[2, 6], => [8, 10],
[8, 10], [15, 18]
[15, 18] ]
]
挑战
O(n log n) 的时间和 O(1) 的额外空间.
/**
* Definition of Interval:
* classs Interval {
* int start, end;
* Interval(int start, int end) {
* this->start = start;
* this->end = end;
* }
*/
class Solution {
public:
/*
* @param intervals: interval list.
* @return: A new interval list.
*/
static bool cmp(Interval & i, Interval & j) {
return i.start < j.start;
}
vector < Interval > merge(vector < Interval > &intervals) {
// write your code here
if (intervals.size() == 0) return intervals;
sort(intervals.begin(), intervals.end(), cmp);
for (int i = 0; i < intervals.size() - 1;) {
Interval cur = intervals[i];
Interval next = intervals[i + 1];
if (next.start <= cur.end) {
if (next.start < cur.start) {
cur.start = next.start;
}
if (next.end > cur.end) {
cur.end = next.end;
}
intervals.erase(intervals.begin() + i + 1);
intervals[i] = cur;
continue;
}
i++;
}
return intervals;
}
};
来源: http://www.bubuko.com/infodetail-2478709.html