代码随想录：合并区间

class Solution {
public:
    static bool cmp(vector<int> a, vector<int> b) { return a[0] < b[0]; }
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        sort(intervals.begin(), intervals.end(), cmp);
        vector<vector<int>> res;
        int left = intervals[0][0];
        int right = intervals[0][1];
        for (int i = 1; i < intervals.size(); i++) {
            if (intervals[i][0] <= right) {
                right = max(intervals[i][1], right);
            } else {
                vector<int> temp(2, 0);
                temp[0] = left;
                temp[1] = right;
                res.push_back(temp);
                left = intervals[i][0];
                right = intervals[i][1];
            }
        }
        vector<int> temp(2, 0);
        temp[0] = left;
        temp[1] = right;
        res.push_back(temp);
        return res;
    }
};