Question

252. Meeting Rooms

中文文档

Description

Given an array of meeting time intervals where intervals[i] = [starti, endi], determine if a person could attend all meetings.

 

Example 1:

Input: intervals = [[0,30],[5,10],[15,20]]
Output: false

Example 2:

Input: intervals = [[7,10],[2,4]]
Output: true

 

Constraints:

• 0 <= intervals.length <= 104
• intervals[i].length == 2
• 0 <= starti < endi <= 106

Solutions

Solution 1

class Solution:
  def canAttendMeetings(self, intervals: List[List[int]]) -> bool:
    intervals.sort()
    return all(a[1] <= b[0] for a, b in pairwise(intervals))

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]) {
        return false;
      }
    }
    return true;
  }
}

class Solution {
public:
  bool canAttendMeetings(vector<vector<int>>& intervals) {
    sort(intervals.begin(), intervals.end(), [](const vector<int>& a, const vector<int>& b) {
      return a[0] < b[0];
    });
    for (int i = 1; i < intervals.size(); ++i) {
      if (intervals[i][0] < intervals[i - 1][1]) {
        return false;
      }
    }
    return true;
  }
};

func canAttendMeetings(intervals [][]int) bool {
  sort.Slice(intervals, func(i, j int) bool {
    return intervals[i][0] < intervals[j][0]
  })
  for i := 1; i < len(intervals); i++ {
    if intervals[i][0] < intervals[i-1][1] {
      return false
    }
  }
  return true
}

function canAttendMeetings(intervals: number[][]): boolean {
  intervals.sort((a, b) => a[0] - b[0]);
  for (let i = 1; i < intervals.length; ++i) {
    if (intervals[i][0] < intervals[i - 1][1]) {
      return false;
    }
  }
  return true;
}

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 {
        return false;
      }
      end = p[1];
    }

    true
  }
}