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;
}
};