数字0到9999转换大写汉字整数程序（C语言实现）

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

#define DEBUG printf
/*========================================================*/

int len_num(int num);   //to judge the length of the number
char* my_itoa(int num, int len); //to transform the number to a string
char* handle_str(char* str_num, int len); //transform num to NUM

/*========================================================*/

int main()
{
float num_test;
int num, len;
char* str_num;
char* str_result;

while(1)
{
printf("Please input a number:  ");

if(!(scanf("%f", &num_test)))
{
printf("Invalid:data type not correct.\n");
break;
}
else
{
num = (int)num_test;

if (num_test != num)
{
printf("Invalid:number type not correct.\n");
printf("number: %f\n", num_test);
}
else if (num == 0)
{
printf("Number: 0\nLength: 1\nResult: 零\n");
}
else if (num_test > 9999 || num_test < 0)
{
printf("Invalid:number overflow.\n");
printf("number: %d\n", num);
}
else
{
len = len_num(num);

str_num = my_itoa(num, len);

str_result = handle_str(str_num, len);

printf("Number: %d\nLength: %d\n", num, len);
printf("Result: %s\n", str_result);

}
}
}
return 0;
}

/*========================================================*/

/*
function:  to get the length of the number
input : the input number, int num
output: the length of the number, int num_len
*/

int len_num(int num)
{
int num_len;

if(num <= 9999 && num >= 1000)
num_len = 4;
else if(num <= 999 && num >= 100)
num_len = 3;
else if(num <= 99 && num >= 10)
num_len = 2;
else if(num <=9 && num >=0)
num_len = 1;
return num_len;
}

/*
function:  to transform number to a string
input : int num, int len
output: char* point to a string
*/

char *my_itoa(int num, int len)
{
char *temp;
int i;
temp =(char*)malloc(sizeof(char)*len);

for (i = 1; i <= 5; i++)
{
if(len-i != -1)
{
temp[len-i] = num % 10 + '0';
//		DEBUG("temp%d %c",i,temp[len-i]);
num  = num / 10;
}
else
return temp;

}
}

/*
function:  to transform num to NUM
input : char* str_num
output: None
*/

char* handle_str(char* str_num, int len)
{
int i=0, k;
char *str_result;

static char num_trans[10][4] = {"零","一","二","三","四","五","六","七","八","九"};
static char num_value[4][4] = {"千","百","十",'\0'};

str_result = (char*)malloc(sizeof(char)*32);

for(k = 4-len; k <=3 ; k++)
{
int j;
j = str_num[i]-'0';
if(!(str_num[i] == '0' && (str_num[i+1] == '0' || i ==len-1)))
strcat(str_result, num_trans[j]);

if(j != 0)
{
strcat(str_result, num_value[k]);
}
i++;
}
return str_result;
}