Leetcode 986. intersection interval list

Subject description:

Given by a number of two closed interval lists, each of which pairs are disjoint interval list and sorted.

Returns the intersection of these two sections of the list.

(Formally, the closed interval  [a, b](where  a <= b) denotes the set of real number x, and a <= x <= b. Intersection of two closed interval is a set of real numbers, or the empty set, or a closed section for example, [1, 3]and [2, 4]the intersection is [2, 3].)

 

Example:

输入：A = [[0,2],[5,10],[13,23],[24,25]], B = [[1,5],[8,12],[15,24],[25,26]]
输出：[[1,2],[5,5],[8,10],[15,23],[24,24],[25,25]]
注意：输入和所需的输出都是区间对象组成的列表，而不是数组或列表。

prompt:

• 0 <= A.length < 1000
• 0 <= B.length < 1000
• 0 <= A[i].start, A[i].end, B[i].start, B[i].end < 10^9

---

solution:

class Solution {
public:
    vector<vector<int>> intervalIntersection(vector<vector<int>>& A, vector<vector<int>>& B) {
        int sz1 = A.size();
        int sz2 = B.size();
        int i = 0, j = 0;
        vector<vector<int>> res;
        while(i < sz1 && j < sz2){
            if(A[i][0] > B[j][1]){
                j++;
            }else if(A[i][1] < B[j][0]){
                i++;
            }else{
                res.push_back({max(A[i][0], B[j][0]), min(A[i][1], B[j][1])});
                if(A[i][1] < B[j][1]){
                    i++;
                }else if(A[i][1] == B[j][1]){
                    i++;
                    j++;
                }else{
                    j++;
                }
            }
        }
        
        return res;
    }
};