poj3067Japan——树状数组查找逆序对

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
int t,n,m,k;
long long f[1005],ans;
struct N{
	long long aa,bb;
}edge[1000005];
bool cmp(N x,N y)
{
	if(x.aa!=y.aa)return x.aa>y.aa;
	else return x.bb>y.bb;
//	if(x.aa!=y.aa)return x.aa<y.aa;
//	else return x.bb<y.bb;
}
long long query(int x)
{
	long long sum=0;
	for(;x;x-=x&-x)
		sum+=f[x];
	return sum;
}
void add(int x)
{
	for(;x<=m;x+=x&-x)
		f[x]++;
}
int main()
{
	scanf("%d",&t);
	for(int g=1;g<=t;g++)
	{
		scanf("%d%d%d",&n,&m,&k);
		for(int i=1;i<=k;i++)
			scanf("%lld%lld",&edge[i].aa,&edge[i].bb);
		sort(edge+1,edge+k+1,cmp);
		memset(f,0,sizeof f);
		ans=0;//!!!
		for(int i=1;i<=k;i++)
		{
			add(edge[i].bb);
			ans+=query(edge[i].bb-1);//-1!
//			add(edge[i].bb);
//			ans+=i-query(edge[i].bb);
		}
		printf("Test case %d: %lld\n",g,ans);
	}
	return 0;
}