leetcode--Merge Intervals

1.题目描述

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].

2.解法分析

题目很简单。只是自定义的排序仿函数要放在solution类外面，否则会出现如下错误：

Line 23: no matching function for call to 'sort(std::vector<Interval>::iterator, std::vector<Interval>::iterator, <unresolved overloaded function type>)'

代码如下：

/** * Definition for an interval. * struct Interval { * int start; * int end; * Interval() : start(0), end(0) {} * Interval(int s, int e) : start(s), end(e) {} * }; */ bool lc(const Interval &a,const Interval &b) { return a.start<b.start; }   class Solution { public:     vector<Interval> merge(vector<Interval> &intervals) { // Start typing your C/C++ solution below // DO NOT write int main() function vector<Interval>result; if(intervals.empty())return result; std::sort(intervals.begin(),intervals.end(),lc); Interval cur=intervals[0]; int len=intervals.size(); if(len==1)return intervals; int i=1; while(i<len) { if(cur.end>=intervals[i].start) { cur.end=max(intervals[i].end,cur.end); } else { result.push_back(cur); cur=intervals[i]; } i++; } if(result.empty()||result.back().end<cur.start)result.push_back(cur); return result; } };