You are given two lists of closed intervals, firstList
and secondList
, where firstList[i] = [starti, endi]
and secondList[j] = [startj, endj]
. Each list of intervals is pairwise disjoint and in sorted order.
Return the intersection of these two interval lists.
A closed interval [a, b]
(with a < b
) denotes the set of real numbers x
with a <= x <= b
.
The intersection of two closed intervals is a set of real numbers that are either empty or represented as a closed interval. For example, the intersection of [1, 3]
and [2, 4]
is [2, 3]
.
Example 1:
Input: firstList = [[0,2],[5,10],[13,23],[24,25]], secondList = [[1,5],[8,12],[15,24],[25,26]] Output: [[1,2],[5,5],[8,10],[15,23],[24,24],[25,25]]
Example 2:
Input: firstList = [[1,3],[5,9]], secondList = [] Output: []
Example 3:
Input: firstList = [], secondList = [[4,8],[10,12]] Output: []
Example 4:
Input: firstList = [[1,7]], secondList = [[3,10]] Output: [[3,7]]
Constraints:
0 <= firstList.length, secondList.length <= 1000
firstList.length + secondList.length >= 1
0 <= starti < endi <= 109
endi < starti+1
0 <= startj < endj <= 109
endj < startj+1
class Solution:
def intervalIntersection(self, firstList: List[List[int]], secondList: List[List[int]]) -> List[List[int]]:
i = j = 0
res = []
while i < len(firstList) and j < len(secondList):
l, r = max(firstList[i][0], secondList[j][0]), min(
firstList[i][1], secondList[j][1])
if l <= r:
res.append([l, r])
if firstList[i][1] < secondList[j][1]:
i += 1
else:
j += 1
return res
class Solution {
public int[][] intervalIntersection(int[][] firstList, int[][] secondList) {
List<int[]> res = new ArrayList<>();
for (int i = 0, j = 0; i < firstList.length && j < secondList.length;) {
int l = Math.max(firstList[i][0], secondList[j][0]);
int r = Math.min(firstList[i][1], secondList[j][1]);
if (l <= r) {
res.add(new int[]{l, r});
}
if (firstList[i][1] < secondList[j][1]) {
++i;
} else {
++j;
}
}
return res.toArray(new int[res.size()][]);
}
}
class Solution {
public:
vector<vector<int>> intervalIntersection(vector<vector<int>> &firstList, vector<vector<int>> &secondList) {
vector<vector<int>> res;
for (int i = 0, j = 0; i < firstList.size() && j < secondList.size();)
{
int l = max(firstList[i][0], secondList[j][0]);
int r = min(firstList[i][1], secondList[j][1]);
if (l <= r)
res.push_back({l, r});
if (firstList[i][1] < secondList[j][1])
++i;
else
++j;
}
return res;
}
};
func intervalIntersection(firstList [][]int, secondList [][]int) [][]int {
i, j := 0, 0
var res [][]int
for i < len(firstList) && j < len(secondList) {
l, r := max(firstList[i][0], secondList[j][0]), min(firstList[i][1], secondList[j][1])
if l <= r {
res = append(res, []int{l, r})
}
if firstList[i][1] < secondList[j][1] {
i++
} else {
j++
}
}
return res
}
func max(a, b int) int {
if a > b {
return a
}
return b
}
func min(a, b int) int {
if a < b {
return a
}
return b
}