区间列表的交集

题目链接：https://leetcode-cn.com/problems/interval-list-intersections/
题目描述：

题解：

class Solution {
public:
    vector<vector<int>> intervalIntersection(vector<vector<int>>& firstList, vector<vector<int>>& secondList) {
        vector<vector<int>> result;
        if(firstList.size() == 0 || secondList.size() == 0)
            return result;
        int i = 0;
        int j = 0;
        while(i < firstList.size() && j < secondList.size())
        {
            int left = max(firstList[i][0], secondList[j][0]);          //子区间左边界
            int right = min(firstList[i][1], secondList[j][1]);         //子区间右边界
            if(left <= right)
                result.push_back({left, right});
            firstList[i][1] > secondList[j][1] ? j++ : i++;             //哪一个区间先结束，指针就先移动
        }
        return result;
    }
};