leetcode: Merge Intervals

AC代码，重新申请一个vector，而不是in-place，就通过了

/** * 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 Solution {public:    vector< Interval> insert( vector< Interval> &res, Interval new_interval){        auto iter = res.begin();        while( iter != res.end()){            if( new_interval.end < iter->start){                res.insert( iter, new_interval);                return res;            }            else if( iter->end < new_interval.start){                ++iter;                continue;            }            else{                new_interval.start = min( iter->start, new_interval.start);                new_interval.end = max( iter->end, new_interval.end);                res.erase(iter);            }        }        res.insert( res.end(), new_interval);        return res;    }     vector<Interval> merge(vector<Interval> &intervals) {        vector< Interval> res;        for( int i = 0; i < intervals.size(); ++i){            insert( res, intervals[i]);        }        return res;    }};

TLE，哪里不够快呢。

还有这里可以不用自己写排序，只需要写个比较函数，然后调用库函数就可以了

/** * 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 Solution {public:    static bool comp(Interval a, Interval b){          return a.start < b.start;      }      vector<Interval> merge(vector<Interval> &intervals) {        if(intervals.size() <= 1)            return intervals;                    sort( intervals.begin(), intervals.end(), comp);         int i = 0;        while( i + 1 < intervals.size()){            if( intervals[i].end < intervals[i+1].start){                ++i;            }            else{                intervals[i+1].start = min( intervals[i].start, intervals[i+1].start);                intervals[i+1].end = max( intervals[i].end, intervals[i+1].end);                intervals.erase( intervals.begin() + i);            }        }        return intervals;    }    /*void swap( vector< Interval> &intervals, int i, int j){        Interval tmp = intervals[i];        intervals[i] = intervals[j];        intervals[j] = tmp;    }    void quicksort( vector< Interval> &intervals, int l, int r){        if( l < r){            int pivot = intervals[0].start;            swap( intervals, 0, r);            int i = l, j = r - 1;            while( true){                while( intervals[i].start < pivot)                    ++i;                while( intervals[j].start > pivot)                    --j;                if( i < j)                    swap( intervals, i, j);                else                    break;            }            swap( intervals, i, r);            quicksort( intervals, l, i-1);            quicksort( intervals, i+1, r);        }    }*/};