my function is not called after giving input to n - c

Question

This might be a silly question, but I am unable to find the solution. Function mat is not being called after giving input to variable n.
#include <stdio.h>
#include <stdlib.h>
int mat(int n)
{
printf("hello");
int temp = n, count = 0;
while (temp != 0)
{
temp = n % 10;
switch (temp)
{
case 1:
count += 2;
break;
case 7:
count += 3;
break;
case 4:
count += 4;
break;
case 2:
case 3:
case 5:
count += 5;
break;
case 6:
case 0:
case 9:
count += 6;
break;
case 8:
count += 7;
break;
}
}
return count;
}
int main(void)
{
int t, n, h;
scanf("%d", &t);
while (t--)
{
scanf("%d", &n);
h = mat(n);
printf("%d\n", h);
}
}
I think something is wrong with scanf but don't know what it is.
this program was to give the output for number of matches being used for particular number.

Answer 1

Forgive me. A common mistake of beginners is to "get into the weeds" without properly considering the nature of a problem. Lines and lines of code are written that fiddle with particular micro-aspects of the problem.
From the OP code, it appears you want to sum various amounts to a total based on the digits found in the user's number. Since 0-9 are "contiguous", a contiguous array of those values (with duplicates) can serve and reduce the amount of code that is copy/paste/adapted. You will spend many more hours READING code than writing code. Try to make the code as simple to understand (and reliable) as possible. Potential bugs will LEAP OFF THE SCREEN when you do this and your code will be appreciated by others.
#include <stdio.h>
#include <stdlib.h>
int mat( int n ) {
printf( "hello\n" );
// contiguous array of 10 values (some repeated)
int incr[] = { 6, 2, 5, 5, 4, 5, 6, 3, 7, 6 };
int count = 0;
// sum from array values based on digits of value received
do {
count += incr[ n % 10 ];
} while( n /= 10 );
return count;
}
int main( void ) {
int t = 0; // ALWAYS initiaialise variables
scanf( "%d", &t );
while( t-- ) {
int n = 0; // declare variables close to use
scanf( "%d", &n );
// No need for 'h'. print returned value directly.
printf( "%d ==> %d\n", n, mat( n ) );
}
}