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feat: add solutions to lc problems: No.0252,0253 #4280

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Mar 22, 2025
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feat: add solutions to lc problems: No.0252,0253 #4280

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39 changes: 9 additions & 30 deletions solution/0200-0299/0252.Meeting Rooms/README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -53,9 +53,9 @@ tags:

### 方法一：排序

我们将会议按照开始时间进行排序，然后遍历排序后的会议，如果当前会议的开始时间小于前一个会议的结束时间，则说明两个会议有重叠，返回 `false` 即可。
我们将会议按照开始时间进行排序，然后遍历排序后的会议，如果当前会议的开始时间小于前一个会议的结束时间，则说明两个会议有重叠，返回 $\text{false}$，否则继续遍历。

遍历结束后，返回 `true`。
如果遍历结束都没有发现重叠的会议，则返回 $\text{true}$。

时间复杂度 $O(n \times \log n)$，空间复杂度 $O(\log n)$。其中 $n$ 为会议数量。

Expand All @@ -77,9 +77,7 @@ class Solution {
public boolean canAttendMeetings(int[][] intervals) {
Arrays.sort(intervals, (a, b) -> a[0] - b[0]);
for (int i = 1; i < intervals.length; ++i) {
var a = intervals[i - 1];
var b = intervals[i];
if (a[1] > b[0]) {
if (intervals[i - 1][1] > intervals[i][0]) {
return false;
}
}
Expand All @@ -94,11 +92,11 @@ class Solution {
class Solution {
public:
bool canAttendMeetings(vector<vector<int>>& intervals) {
sort(intervals.begin(), intervals.end(), [](const vector<int>& a, const vector<int>& b) {
ranges::sort(intervals, [](const auto& a, const auto& b) {
return a[0] < b[0];
});
for (int i = 1; i < intervals.size(); ++i) {
if (intervals[i][0] < intervals[i - 1][1]) {
if (intervals[i - 1][1] > intervals[i][0]) {
return false;
}
}
Expand Down Expand Up @@ -141,32 +139,13 @@ function canAttendMeetings(intervals: number[][]): boolean {

```rust
impl Solution {
#[allow(dead_code)]
pub fn can_attend_meetings(intervals: Vec<Vec<i32>>) -> bool {
if intervals.len() == 1 {
return true;
}

let mut intervals = intervals;

// Sort the intervals vector
intervals.sort_by(|lhs, rhs| lhs[0].cmp(&rhs[0]));

let mut end = -1;

// Begin traverse
for p in &intervals {
if end == -1 {
// This is the first pair
end = p[1];
continue;
}
if p[0] < end {
pub fn can_attend_meetings(mut intervals: Vec<Vec<i32>>) -> bool {
intervals.sort_by(|a, b| a[0].cmp(&b[0]));
for i in 1..intervals.len() {
if intervals[i - 1][1] > intervals[i][0] {
return false;
}
end = p[1];
}

true
}
}
Expand Down
43 changes: 14 additions & 29 deletions solution/0200-0299/0252.Meeting Rooms/README_EN.md
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Expand Up @@ -42,7 +42,13 @@ tags:

<!-- solution:start -->

### Solution 1
### Solution 1: Sorting

We sort the meetings based on their start times, and then iterate through the sorted meetings. If the start time of the current meeting is less than the end time of the previous meeting, it indicates that there is an overlap between the two meetings, and we return `false`. Otherwise, we continue iterating.

If no overlap is found by the end of the iteration, we return `true`.

The time complexity is $O(n \times \log n)$, and the space complexity is $O(\log n)$, where $n$ is the number of meetings.

<!-- tabs:start -->

Expand All @@ -62,9 +68,7 @@ class Solution {
public boolean canAttendMeetings(int[][] intervals) {
Arrays.sort(intervals, (a, b) -> a[0] - b[0]);
for (int i = 1; i < intervals.length; ++i) {
var a = intervals[i - 1];
var b = intervals[i];
if (a[1] > b[0]) {
if (intervals[i - 1][1] > intervals[i][0]) {
return false;
}
}
Expand All @@ -79,11 +83,11 @@ class Solution {
class Solution {
public:
bool canAttendMeetings(vector<vector<int>>& intervals) {
sort(intervals.begin(), intervals.end(), [](const vector<int>& a, const vector<int>& b) {
ranges::sort(intervals, [](const auto& a, const auto& b) {
return a[0] < b[0];
});
for (int i = 1; i < intervals.size(); ++i) {
if (intervals[i][0] < intervals[i - 1][1]) {
if (intervals[i - 1][1] > intervals[i][0]) {
return false;
}
}
Expand Down Expand Up @@ -126,32 +130,13 @@ function canAttendMeetings(intervals: number[][]): boolean {

```rust
impl Solution {
#[allow(dead_code)]
pub fn can_attend_meetings(intervals: Vec<Vec<i32>>) -> bool {
if intervals.len() == 1 {
return true;
}

let mut intervals = intervals;

// Sort the intervals vector
intervals.sort_by(|lhs, rhs| lhs[0].cmp(&rhs[0]));

let mut end = -1;

// Begin traverse
for p in &intervals {
if end == -1 {
// This is the first pair
end = p[1];
continue;
}
if p[0] < end {
pub fn can_attend_meetings(mut intervals: Vec<Vec<i32>>) -> bool {
intervals.sort_by(|a, b| a[0].cmp(&b[0]));
for i in 1..intervals.len() {
if intervals[i - 1][1] > intervals[i][0] {
return false;
}
end = p[1];
}

true
}
}
Expand Down
6 changes: 3 additions & 3 deletions solution/0200-0299/0252.Meeting Rooms/Solution.cpp
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Original file line number Diff line number Diff line change
@@ -1,14 +1,14 @@
class Solution {
public:
bool canAttendMeetings(vector<vector<int>>& intervals) {
sort(intervals.begin(), intervals.end(), [](const vector<int>& a, const vector<int>& b) {
ranges::sort(intervals, [](const auto& a, const auto& b) {
return a[0] < b[0];
});
for (int i = 1; i < intervals.size(); ++i) {
if (intervals[i][0] < intervals[i - 1][1]) {
if (intervals[i - 1][1] > intervals[i][0]) {
return false;
}
}
return true;
}
};
};
6 changes: 2 additions & 4 deletions solution/0200-0299/0252.Meeting Rooms/Solution.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,10 @@ class Solution {
public boolean canAttendMeetings(int[][] intervals) {
Arrays.sort(intervals, (a, b) -> a[0] - b[0]);
for (int i = 1; i < intervals.length; ++i) {
var a = intervals[i - 1];
var b = intervals[i];
if (a[1] > b[0]) {
if (intervals[i - 1][1] > intervals[i][0]) {
return false;
}
}
return true;
}
}
}
27 changes: 4 additions & 23 deletions solution/0200-0299/0252.Meeting Rooms/Solution.rs
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Original file line number Diff line number Diff line change
@@ -1,30 +1,11 @@
impl Solution {
#[allow(dead_code)]
pub fn can_attend_meetings(intervals: Vec<Vec<i32>>) -> bool {
if intervals.len() == 1 {
return true;
}

let mut intervals = intervals;

// Sort the intervals vector
intervals.sort_by(|lhs, rhs| lhs[0].cmp(&rhs[0]));

let mut end = -1;

// Begin traverse
for p in &intervals {
if end == -1 {
// This is the first pair
end = p[1];
continue;
}
if p[0] < end {
pub fn can_attend_meetings(mut intervals: Vec<Vec<i32>>) -> bool {
intervals.sort_by(|a, b| a[0].cmp(&b[0]));
for i in 1..intervals.len() {
if intervals[i - 1][1] > intervals[i][0] {
return false;
}
end = p[1];
}

true
}
}
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