POJ 2352 树状数组

这是一道YY题= =...

确实.. 做这题我就是YY出来的。一交没想到1Y了~ 哈哈哈~ 笑死我了~

树状数组再练一道就罢手！

#include<iostream>
#include<algorithm>
#include<cstdio>
using namespace std;

int c[15555],n,lev[15555];
struct point
{
 	   int x,y,pos;
}p[15555];

bool cmp1( point a,point b )
{
 	 if( a.x==b.x )
 	 	 return a.y<b.y;
 	 return a.x<b.x;
}
bool cmp2( point a,point b )
{
 	 if( a.y==b.y )
 	 	 return a.x<b.x;
 	 return a.y<b.y;
}

int lowbit( int x ){ return x&-x; }
int sum( int x )
{
 	int rec=0;
 	while( x )
 	{
	 	   rec+=c[x];
	 	   x-=lowbit(x);
  	}
  	return rec;
}
void add( int x,int v )
{
 	 while( x<=n )
 	 {
	  		c[x]+=v;
	  		x+=lowbit(x);
	 }
}

int main()
{
 	while( scanf("%d",&n)!=EOF )
 	{
	 	   memset( c,0,sizeof(c) );
	 	   memset(lev,0,sizeof(lev));
	 	   for( int i=0;i<n;i++ )
	 	   		scanf( "%d%d",&p[i].x,&p[i].y );
	 	   sort( p,p+n,cmp1 );
	 	   for( int i=0;i<n;i++ )
	 	   		p[i].pos=i+1;
	 	   sort( p,p+n,cmp2 );
	 	   for( int i=0;i<n;i++ )
	 	   {
		   		//printf( "pos:%d\n",p[i].pos );
	 	   		lev[sum(p[i].pos)]++;
	 	   		add( p[i].pos,1 );
		   }
		   for( int i=0;i<n;i++ )
		   		printf( "%d\n",lev[i] );
  	}
 	return 0;
}