赛后总结

L2-2

• 思路：
• 比赛的时候以为是区间合并，写完之后发现并不是，最后十分钟想到是活动安排，发现活动安排不会写
• 看了题解，竟然是差分，太神奇了
• 但是还是没太理解为啥找到最大重合的就可以了

#include <bits/stdc++.h>
//#define int long long
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
using namespace std;
int a[N];

signed main()
{
    int n;
    cin >> n;
    for(int i = 1; i <= n; i ++)
    {
        int hh, mm, ss;
        scanf("%d:%d:%d", &hh, &mm, &ss);
        int st = hh * 3600 + mm * 60 + ss;
        scanf("%d:%d:%d", &hh, &mm, &ss);
        int ed = hh * 3600 + mm * 60 + ss;
        a[st] ++;
        a[ed + 1] --;
    }
    int res = -1;
    int all_time = 24 * 60 * 60;
    for(int i = 0; i <= all_time; i ++)
    {
        a[i] = a[i - 1] + a[i];
        res = max(res, a[i]);
    }
    cout << res << endl;
    return 0;
}