C language programming

Code

# Include "stdafx. H"
Typedef int (* pfun) (int A, int B );
Int isnumberequal (INT number );
Void ntos (INT number, int C []);
Void sort (int A [], pfun PF );
Int getmaxn (int A []);
Int getminn (int B []);

Int ASC (int A, int B) {return (A> B? 1:0 );}
Int DESC (int A, int B) {return (A <B? 1:0 );}

Int main (INT argc, char * argv [])
{
Int num = 0;
Printf ("Please enter a number :");
Scanf ("% d", & num );
// When isnumberequal is called, if the number is not 4 bits, or there is danger, put it at the end and return a short circuit.
While (Num <1000 | num> 9999 | isnumberequal (Num )){
Printf ("invalid number: % d, try again: \ n", num );
Scanf ("% d", & num );
}
Int arr [4], Max, min;
Do {
Ntos (Num, arr );
Max = getmaxn (ARR );
Printf ("max = % d,", max );
Min = getminn (ARR );
Printf ("min = % d \ n", min );
Num = max-min;
} While (num! = 6174 );

Printf ("\ n max (% d)-min (% d) = % d \ n", Max, Min, max-min );
Printf ("\ ndone ");
Return 0;
}
// Use the int isnumberequal (INT number) function to check whether the numbers of the input integer numbers are not equal,
// Returns an equal value of 1. Otherwise, the return value is 0;
Int isnumberequal (INT number)
{
Int A [4] = {0 ,};
Ntos (number, );
Int IRES = 0;
For (INT I = 0; I <4; ++ I ){
For (Int J = I + 1; j <4; ++ J ){
If (A [I] = A [J]) {
IRES = 1;
Break;
}
}
If (IRES = 1) break;
}
Return IRES;
}

// Use a function (void ntos (INT number, int C []) to store the four-digit integer number into array C
Void ntos (INT number, int C [])
{
For (INT I = 0; number> 0; ++ I ){
C [I] = Number % 10;
Number/= 10;
}
}
// Use the function (void sort (int A []) to sort array a of four elements (both in ascending or descending order );
Void sort (int A [], pfun PF)
{
// Select Method
For (INT I = 0; I <4; ++ I ){
For (Int J = I + 1; j <4; ++ J ){
If (PF (A [I], a [J]) {
Int T = A [I];
A [I] = A [J];
A [J] = T;
}
}
}
}

// The returned value is the maximum value.
Int getmaxn (int A [])
{
Int sum = 0, POW = 1;
Sort (A, DESC );
For (INT I = 3; I> = 0; -- I, Pow * = 10 ){
Sum + = A [I] * POW;
}
Return sum;
}
// The return value is the minimum value.
Int getminn (int A [])
{
Int sum = 0, POW = 1;
Sort (A, ASC );
For (INT I = 3; I> = 0; -- I, Pow * = 10 ){
Sum + = A [I] * POW;
}
Return sum;
}