written_amount(打印数字）

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

static char	*digits[] = {
	"", "ONE ", "TWO ", "THREE ", "FOUR ", "FIVE ", "SIX ", "SEVEN ",
	"EIGHT ", "NINE ", "TEN ", "ELEVEN ", "TWELVE ", "THIRTEEN ",
	"FOURTEEN ", "FIFTEEN ", "SEXTEEN ", "SEVENTEEN ", "EIGHTEEN ",
	"NINETEEN "
};

static char *tens[] = {
	"", "", "TWENTY ", "THIRTY ", "FORTY ", "FIFTY ", "SIXTY ", "SEVENTY ",
	"EIGHTY ", "NINETY "
};

static char *magnitudes[] = {
	"", "THOUSAND ", "MILLION ", "BILLION "
};

static void
do_one_group( unsigned int amount, char *buffer, char **magnitude )
{
	int		value;

	value = amount / 1000;
	if( value > 0 )
		do_one_group( value, buffer, magnitude + 1 );

	amount %= 1000;
	value = amount / 100;
	if( value > 0 )
	{
		strcat( buffer, digits[ value ] );
		strcat( buffer, "HUNDRED " );
	}

	value = amount % 100;

	if( value >= 20 )
	{
		strcat( buffer, tens[ value / 10 ] );
		value %= 10;
	}
	if( value > 0 )
		strcat( buffer, digits[ value ] );

	if( amount > 0 )
		strcat( buffer, *magnitude );
}

void 
written_amount( unsigned int amount, char *buffer )
{
	if( amount == 0 )
		strcpy (buffer, "ZERO ");
	else
	{
		*buffer = '\0';						//  重要，必须赋值初始化;
		do_one_group( amount, buffer, magnitudes );
	}
}

int 
main()
{
	unsigned int		amount;
	char    buffer[ 256 ];
	printf( "请输入支票金额阿拉伯数字 ： " );
	scanf( "%u", &amount );
	written_amount( amount, buffer );
    printf( "\n %s ", buffer );	
	return 0;
}