桶排序

#include<stdio.h>
#include<string.h>

int a[10010],w[10010],p[10010],o[10010];

void Barrel_Sort( int *a , int n ,int mx )
{
    int i ;
    memset ( w , 0 , sizeof(w) ) ;
    for ( i = 1 ; i <= n ; i++ )
        w[ a[i] ]++;
    for ( i = 1 ; i <= mx ; i++ )
        w[i] = w[i] + w[i-1] ;
    for ( i = 1 ; i <= n ; i++ ) {
        p[i] = w[a[i]] ;
        w[a[i]]--;
    }
    for( i = 1 ; i <= n ; i++ )
        o[p[i]] = i;
}

int main()
{
    int n,i,mx;
    while ( scanf("%d" , &n) != EOF ) {

    mx = 0;
    for( i = 1 ; i <= n ; i++ )
    {
        scanf ("%d" , &a[i] );
        if ( a[i] > mx )
            mx = a[i];
    }
    Barrel_Sort( a , n , mx );
    for ( i = 1 ; i <= n ; i++ )
    {
        printf ("%d " , a[o[i]] );
    }
    printf ("
");
    
    }
    return 0;
}
    

桶排序为复杂度为O(n +　ｋ)，其中k为所排数的最大值 。