标签:style blog color art cti for
Given a collection of intervals, merge all overlapping intervals.
For example,
Given [1,3],[2,6],[8,10],[15,18]
,
return [1,6],[8,10],[15,18]
.
题目的意思是将相交得区间合并,典型的贪心算法
首先将区间先按照start进行排序,
然后保存先前区间的start和end
如果当前的start > 先前的end,说明当前的区间与之前的区间不想交,则将先前的区间放入结果中,同时更新start和end
如果当前的start < 先前的end,说明当前的区间与先前的区间相交,故比较当前的end与先前的end,如果当前的end大于先前的end,则更新先前的end为当前的end
bool cmp(const Interval& a, const Interval& b){ if(a.start!=b.start) return a.start < b.start; else return a.end < b.end; } class Solution { public: vector<Interval> merge(vector<Interval> &intervals) { sort(intervals.begin(), intervals.end(), cmp); vector<Interval> res; if(intervals.size() == 0) return res; int start = intervals[0].start, end = intervals[0].end; for(int i = 1 ; i < intervals.size(); ++ i){ if(intervals[i].start > end){ res.push_back(Interval(start,end)); start = intervals[i].start, end = intervals[i].end; }else{ end = max(end, intervals[i].end); } } res.push_back(Interval(start,end)); return res; } };
Leetcode Merge Intervals,布布扣,bubuko.com
标签:style blog color art cti for
原文地址:http://www.cnblogs.com/xiongqiangcs/p/3825951.html