给定两个由一些 闭区间 组成的列表,firstList
和 secondList
,其中 firstList[i] = [starti, endi]
而 secondList[j] = [startj, endj]
。每个区间列表都是成对 不相交 的,并且 已经排序 。
返回这 两个区间列表的交集 。
形式上,闭区间 [a, b]
(其中 a <= b
)表示实数 x
的集合,而 a <= x <= b
。
两个闭区间的 交集 是一组实数,要么为空集,要么为闭区间。例如,[1, 3]
和 [2, 4]
的交集为 [2, 3]
。
示例 1:
输入:firstList = [[0,2],[5,10],[13,23],[24,25]], secondList = [[1,5],[8,12],[15,24],[25,26]] 输出:[[1,2],[5,5],[8,10],[15,23],[24,24],[25,25]]
示例 2:
输入:firstList = [[1,3],[5,9]], secondList = [] 输出:[]
示例 3:
输入:firstList = [], secondList = [[4,8],[10,12]] 输出:[]
示例 4:
输入:firstList = [[1,7]], secondList = [[3,10]] 输出:[[3,7]]
提示:
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
双指针实现区间合并。
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
}