Count Days Without Meetings

class Solution {
public:
    int countDays(int days, vector<vector<int>>& meetings) {
        sort(meetings.begin(), meetings.end());
        long long busy = 0;
        int curStart = -1, curEnd = -1;
        for (auto& m : meetings) {
            if (m[0] > curEnd) {
                busy += curEnd - curStart + 1;
                curStart = m[0];
                curEnd = m[1];
            } else {
                curEnd = max(curEnd, m[1]);
            }
        }
        if (curStart >= 0) busy += curEnd - curStart + 1;
        return days - busy;
    }
};

import "sort"

func countDays(days int, meetings [][]int) int {
    sort.Slice(meetings, func(i, j int) bool {
        if meetings[i][0] != meetings[j][0] {
            return meetings[i][0] < meetings[j][0]
        }
        return meetings[i][1] < meetings[j][1]
    })
    busy := 0
    curStart, curEnd := -1, -1
    for _, m := range meetings {
        if m[0] > curEnd {
            busy += curEnd - curStart + 1
            curStart = m[0]
            curEnd = m[1]
        } else if m[1] > curEnd {
            curEnd = m[1]
        }
    }
    if curStart >= 0 {
        busy += curEnd - curStart + 1
    }
    return days - busy
}

from typing import List

class Solution:
    def countDays(self, days: int, meetings: List[List[int]]) -> int:
        meetings.sort()
        busy = 0
        cur_start, cur_end = -1, -1
        for m in meetings:
            if m[0] > cur_end:
                busy += cur_end - cur_start + 1
                cur_start = m[0]
                cur_end = m[1]
            elif m[1] > cur_end:
                cur_end = m[1]
        if cur_start >= 0:
            busy += cur_end - cur_start + 1
        return days - busy

function countDays(days, meetings) {
    meetings.sort((a, b) => a[0] - b[0] || a[1] - b[1]);
    let busy = 0;
    let curStart = -1, curEnd = -1;
    for (const m of meetings) {
        if (m[0] > curEnd) {
            busy += curEnd - curStart + 1;
            curStart = m[0];
            curEnd = m[1];
        } else if (m[1] > curEnd) {
            curEnd = m[1];
        }
    }
    if (curStart >= 0) busy += curEnd - curStart + 1;
    return days - busy;
}

class Solution {
    public int countDays(int days, int[][] meetings) {
        Arrays.sort(meetings, (a, b) -> a[0] != b[0] ? a[0] - b[0] : a[1] - b[1]);
        int busy = 0;
        int curStart = -1, curEnd = -1;
        for (int[] m : meetings) {
            if (m[0] > curEnd) {
                busy += curEnd - curStart + 1;
                curStart = m[0];
                curEnd = m[1];
            } else if (m[1] > curEnd) {
                curEnd = m[1];
            }
        }
        if (curStart >= 0) busy += curEnd - curStart + 1;
        return days - busy;
    }
}

function countDays(days: number, meetings: number[][]): number {
    meetings.sort((a, b) => a[0] - b[0] || a[1] - b[1]);
    let busy = 0;
    let curStart = -1, curEnd = -1;
    for (const m of meetings) {
        if (m[0] > curEnd) {
            busy += curEnd - curStart + 1;
            curStart = m[0];
            curEnd = m[1];
        } else if (m[1] > curEnd) {
            curEnd = m[1];
        }
    }
    if (curStart >= 0) busy += curEnd - curStart + 1;
    return days - busy;
}