HDU 2020 绝对值排序 堆优化

用二叉排序树写一个

#include<stdio.h>
typedef struct Node
{
	int data;
	struct Node *lc,*rc;
}node,*Link;
int n,f;
inline int fab( int a )
{
	return a > 0 ? a : -a;
}
void insert( Link *L,int x )
{
	if( *L )
	{
		if( fab( x ) > fab( ( *L ) -> data ) )
			insert( &( *L ) -> lc,x );
		else
			insert( &( *L ) -> rc,x );
	}
	else
	{
		*L = new node;
		( *L ) -> data = x;
		( *L ) -> lc = ( *L ) -> rc = NULL;
	}
}
void print( Link L )
{
	if( L )
	{
		print( L -> lc );
		printf( f++ == 0 ? "%d" : " %d",L -> data );
		print( L -> rc );
	}
}
int main( )
{
	while( scanf( "%d",&n ),n )
	{
		Link L;
		L = NULL;
		int x;
		f = 0;
		for( int i = 0; i < n; ++i )
			scanf( "%d",&x ),insert( &L,x );
		print( L );
		puts( "" );
	}
	return 0;
}

用堆写一个

#include<stdio.h>
int c,num[105],n;
inline int fab( int a )
{
    return a > 0 ? a : -a;
}
void swap( int i,int j )
{
    int c;
    c = num[i];
    num[i] = num[j];
    num[j] = c;
}
void up( int x )
{
    if( x > 1 )
    {
        int p = x / 2;
        if( fab( num[x] ) > fab( num[p] ) )
            swap( x,p ),up( p );
    }
}
void down( int x )
{
    int p = x * 2;
    if( p <= c )//这里是p <= c
    {
        if( p + 1 <= c )
            p = fab( num[p] ) > fab( num[p+1] ) ? p : p + 1;
        if( fab( num[p] ) > fab( num[x] ) )
            swap( x,p ),down( p );
    }
}
int pop(  )
{
    int x = num[1];
    swap( 1,c-- );
    down( 1 );
    return x;
}
int main(  )
{
    while( scanf( "%d",&n ),n )
    {
        for( int i = 1; i <= n; ++i )
            scanf( "%d",&num[i] ),up( i );
        c = n;
        for( int i = 1; i <= n; ++i )
            printf( i == 1 ? "%d": " %d",pop(  ) );
        puts( "" );
    }
    return 0;
}