合并区间
双指针算法、位运算、离散化、区间合并_小雪菜本菜的博客-CSDN博客
class Solution {
public:vector<vector<int>> merge(vector<vector<int>>& a) {vector<vector<int>> res;if(a.empty()) return res;sort(a.begin(),a.end());int l = a[0][0],r = a[0][1];for(int i = 0;i < a.size();i++ ) {if(a[i][0] > r) {res.push_back({l,r});l = a[i][0],r = a[i][1];} else r = max(r,a[i][1]);}res.push_back({l,r});return res;}
};
