# include & ltstdio.h & gt

int main()

{

int a，b；

int I；

Printf ("Please enter a number:");

scanf("%d "，& ampa)；

b = a；

for(I = 0； a & gt 1; i++)

{

a = a/ 10；

}

Printf("%d is %d digits \n ",b, i);

}

Extended data:

A detailed explanation of the idea:

In C language, integer division is often used to determine the specific number of bits of an integer. Similarly, integer division can be used here to determine the number of digits of a number.

First, use the scanf function to get the value of this number and assign it to the variable B for backup.

Then, the core idea is that when a number is divisible by 10 and the first result is 1, the number is a single digit. Therefore, it is regarded as the subject in the loop.

get for(I = 0； a & gt 1; i++)a = a/ 10； Such code can eventually output results.