1, enter a positive integer.

2. Convert an integer into a string (using the sprintf function)

3. Find the length of the string (strlen function), that is, the number of digits of a positive integer.

The code is as follows:

# Contains? & ltstdio.h & gt

# Contains? & ltstring.h & gt

int？ Master ()

{

Dragon? num

Charles? str[20]；

scanf("%ld "，& ampnum)；

sprintf(str，" %ld "，num)；

printf("%d "，strlen(str))；

Return? 0;

} This writing mainly takes into account that there may be 0 before the integer, such as 00090, which is a two-digit number. If you confirm that there is no leading 0, you can simplify the process, omit the process of converting into a string, and get the string directly with gets.