线段的重叠

 1 #include <bits/stdc++.h>
 2 #define _xx ios_base::sync_with_stdio(0);cin.tie(0);
 3 using namespace std;
 4 typedef long long ll;
 5 struct node
 6 {
 7     int s, e;
 8 } a[50005];
 9 bool operator < (const node& t1, const node& t2)
10 {
11     return t1.s < t2.s;
12 }
13 int main()
14 {_xx
15     int n, ans = 0;
16     cin >> n;
17     for(int i = 1; i <= n; i++) cin >> a[i].s >> a[i].e;
18     sort(a + 1, a + n + 1);
19     int lmost = 0;
20     for(int i = 1; i <= n; i++)
21     {
22         if(lmost <= a[i].e) ans = max(ans, lmost - a[i].s);
23         else ans = max(ans, a[i].e - a[i].s);
24         lmost = max(lmost, a[i].e);
25     }
26     cout << ans << endl;
27     return 0;
28 }