C++ 解法, 执行用时: 43ms, 内存消耗: 14264KB, 提交时间: 2022-07-13

/**
 * Definition for an interval.
 * struct Interval {
 *     int start;
 *     int end;
 *     Interval() : start(0), end(0) {}
 *     Interval(int s, int e) : start(s), end(e) {}
 * };
 */
static const auto io_sync_off = []()
{
    std::ios::sync_with_stdio(false);//关闭输入输出
    std::cin.tie(nullptr);//取消两个stream绑定
    std::cout.tie(nullptr);//取消cin 和 cout之间的绑定,加快执行效率
    return nullptr;
}();
 
class Solution {
public:
    vector<Interval> merge(vector<Interval>& intervals) {
        if (intervals.size() < 2)
            return intervals;
        sort(intervals.begin(), intervals.end(), [](Interval a, Interval b) {return a.start < b.start; });
        Interval inter = intervals[0];
        vector<Interval> ans;
        for (int i = 1; i < intervals.size(); i++)
        {
            if (intervals[i].start <= inter.end)
            {
                inter.end = inter.end < intervals[i].end ? intervals[i].end : inter.end;              
            }
            else
            {
                ans.push_back(inter);
                inter = intervals[i];
            }
        }
        ans.push_back(inter);
        return ans;
    }
};

C++ 解法, 执行用时: 43ms, 内存消耗: 16208KB, 提交时间: 2022-06-21

/**
 * Definition for an interval.
 * struct Interval {
 *     int start;
 *     int end;
 *     Interval() : start(0), end(0) {}
 *     Interval(int s, int e) : start(s), end(e) {}
 * };
 */

static const auto io_sync_off = []()
{
    std::ios::sync_with_stdio(false);//关闭输入输出
    std::cin.tie(nullptr);//取消两个stream绑定
    std::cout.tie(nullptr);//取消cin 和 cout之间的绑定,加快执行效率
    return nullptr;
}();

class Solution {
public:
    vector<Interval> merge(vector<Interval>& intervals) {
        if (intervals.size() < 2)
            return intervals;
        sort(intervals.begin(), intervals.end(), [](Interval a, Interval b) {return a.start < b.start; });
        Interval inter = intervals[0];
        vector<Interval> ans;
        for (int i = 1; i < intervals.size(); i++)
        {
            if (intervals[i].start <= inter.end)
            {
                inter.end = inter.end < intervals[i].end ? intervals[i].end : inter.end;               
            }
            else
            {
                ans.push_back(inter);
                inter = intervals[i];
            }
        }
        ans.push_back(inter);
        return ans;
    }
};

C++ 解法, 执行用时: 44ms, 内存消耗: 13524KB, 提交时间: 2022-06-28

static const auto io_sync_off = []()
{
    std::ios::sync_with_stdio(false);//关闭输入输出
    std::cin.tie(nullptr);//取消两个stream绑定
    std::cout.tie(nullptr);//取消cin 和 cout之间的绑定,加快执行效率
    return nullptr;
}();
class Solution {
public:
	vector<Interval> merge(vector<Interval> &intervals) {
		vector<Interval> ret;
		int len = intervals.size();
		sort(intervals.begin(), intervals.end(), [](Interval& a, Interval& b) {return a.start < b.start; });
		intervals.push_back(Interval(INT_MAX, INT_MAX));
		for (int i = 0; i < len; i++)
		{
			if (intervals[i].end >= intervals[i + 1].end)
			{
				intervals[i + 1]=intervals[i];
			}
			else if(intervals[i].end >= intervals[i + 1].start)
			{
				intervals[i + 1].start = intervals[i].start;
			}
			else
			{
				ret.push_back(intervals[i]);
			}
		}
		return ret;
	}
};

C++ 解法, 执行用时: 46ms, 内存消耗: 13388KB, 提交时间: 2022-07-31

/**
 * Definition for an interval.
 * struct Interval {
 *     int start;
 *     int end;
 *     Interval() : start(0), end(0) {}
 *     Interval(int s, int e) : start(s), end(e) {}
 * };
 */
static const auto io_sync_off = []()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
    return nullptr;
}();
 
class Solution
{
public:
    vector<Interval> merge(vector<Interval> &intervals)
    {
        if (intervals.size() < 2)
            return intervals;
        sort(intervals.begin(), intervals.end(), [](Interval a, Interval b)
             { return a.start < b.start; });
        vector<Interval> results;
        results.push_back(intervals[0]);
        for (int i = 1; i < intervals.size(); i++)
        {
            if (intervals[i].start <= results.back().end)
            {
                results.back().end = results.back().end >= intervals[i].end ? results.back().end : intervals[i].end;
            }
            else
            {
                results.push_back(intervals[i]);
            }
        }
        return results;
    }
};

C++ 解法, 执行用时: 46ms, 内存消耗: 14032KB, 提交时间: 2022-07-05

/**
 * Definition for an interval.
 * struct Interval {
 *     int start;
 *     int end;
 *     Interval() : start(0), end(0) {}
 *     Interval(int s, int e) : start(s), end(e) {}
 * };
 */

static const auto io_sync_off = []()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr); 
    std::cout.tie(nullptr);
    return nullptr;
}();

class Solution {
public:
    vector<Interval> merge(vector<Interval>& intervals) {
        if (intervals.size() < 2)
            return intervals;
        sort(intervals.begin(), intervals.end(), [](Interval a, Interval b) {return a.start < b.start; });
        Interval inter = intervals[0];
        vector<Interval> ans;
        for (int i = 1; i < intervals.size(); i++)
        {
            if (intervals[i].start <= inter.end)
            {
                inter.end = inter.end < intervals[i].end ? intervals[i].end : inter.end;               
            }
            else
            {
                ans.push_back(inter);
                inter = intervals[i];
            }
        }
        ans.push_back(inter);
        return ans;
    }
};