POJ——T 3067 Japan

 1 #include <algorithm>
 2 #include <cstring>
 3 #include <cstdio>
 4 
 5 using namespace std;
 6 
 7 const int N(1111);
 8 int n,m,k,tr[N];
 9 struct Node
10 {
11     int west,east;
12 }node[N*N];
13 bool cmp(Node a,Node b)
14 {
15     if(a.east==b.east) return a.west>b.west;
16     return a.east>b.east;
17 }
18 
19 #define lowbit(x) (x&((~x)+1))
20 inline void Update(int i,int x)
21 {
22     for(;i<=N;i+=lowbit(i)) tr[i]+=x;
23 }
24 inline int Query(int x)
25 {
26     int ret=0;
27     for(;x;x-=lowbit(x)) ret+=tr[x];
28     return ret;
29 }
30 
31 int main()
32 {
33     int t; scanf("%d",&t); int h=1;
34     for(long long ans=0;h<=t;h++,ans=0)
35     {
36         scanf("%d%d%d",&n,&m,&k);
37         for(int i=1;i<=k;i++)
38             scanf("%d%d",&node[i].west,&node[i].east);
39         sort(node+1,node+k+1,cmp);
40         memset(tr,0,sizeof(tr));
41         for(int i=1;i<=k;Update(node[i++].west,1))
42             ans+=(long long)Query(node[i].west-1);
43         printf("Test case %d: %I64d\n",h,ans);
44     }
45     return 0;
46 }