NOIP 2013 火柴排队 程序

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 const int MAXN = 100000 + 1;
 4 const int MOD = 99999997;
 5 int n, F[MAXN], C[MAXN];
 6 struct node
 7 {
 8     int N, H;
 9 }Match1[MAXN], Match2[MAXN];
10 void Update(int x)
11 {
12     for (int i = x; i <= n; i += i&(-i))
13         F[i]++;
14 }
15 int Query(int x)
16 {
17     int S = 0;
18     for (int i = x; i > 0; i -= i&(-i))
19         S += F[i];
20     return S;
21 }
22 bool comp(node x, node y)
23 {
24     return x.H < y.H;
25 }
26 int main()
27 {
28     cin >> n;
29     for (int i = 1; i <= n; i++)
30     {
31         cin >> Match1[i].H;
32         Match1[i].N = i;
33     }
34     for (int i = 1; i <= n; i++)
35     {
36         cin >> Match2[i].H;
37         Match2[i].N = i;
38     }
39     sort(Match1 + 1, Match1 + (n+1), comp);
40     sort(Match2 + 1, Match2 + (n+1), comp);
41     for (int i = 1; i <= n; i++)
42     {
43         C[Match1[i].N] = Match2[i].N;
44     }
45     int Sum = 0;
46     for (int i = 1; i <= n; i++)
47     {
48         Update(C[i]);
49         Sum += i-Query(C[i]);
50         Sum %= MOD;
51     }
52     cout << Sum << endl;
53     return 0;
54 }