LeetCode--Merge Intervals

简单题：先按左左边排序，然后对输入的区间和当前结果合并

/**
 * 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 cmp
{
    public:
    bool operator()(const Interval&a,const Interval&b)
    {
        return a.start < b.start;
    }
};
bool comp(const Interval &lhs, const Interval &rhs)
 {
     return lhs.start < rhs.start;
 }
class Solution {
public:
    vector<Interval> merge(vector<Interval> &intervals) {
        sort(intervals.begin(),intervals.end(),cmp());
        vector<Interval> ret;
        int i;
        for(i = 0 ; i < intervals.size() ; ++i)
        {
            if(i == 0)
            {
                ret.push_back(intervals[0]);
            }
            else
            {
                int size = ret.size();
                 if (ret[size-1].start <= intervals[i].start && intervals[i].start <= ret[size-1].end)
                     ret[size-1].end = max(ret[size-1].end, intervals[i].end);
                 else
                     ret.push_back(intervals[i]);
            }
        }
        return ret;
    }
};