Just learning, problem with an excercise.

I have to do a program that evaluates if the digits of a number are alternatingly evens and odds. Example = 23232, 1234, 9634, etc.

Code:

#include <stdio.h>

int main()
{
	int a;
	int cont=0;
	printf("Ingrese un entero :");
	scanf("%i",&a);
	
	int temp=a;
	
	while(temp>0)
	{
		temp=temp/10;
		cont++;
	}
	
	printf("\n Número de dígitos : %d",cont);
	
	int arr[cont], dig=(temp%10), i=0;
	temp=a;
	
	while (i<cont){
		if (dig%2==0){
		arr[i]=0;
		i++;
		temp=temp/10;
		dig=temp%10;}
		
		else if (dig%2!=0){
			arr[i]=1;
			i++;
			temp=temp/10;
			dig=temp%10;}
		}
		
	i=0;
	int t=(i+1), alter;
	
	while (i<cont){
		if (arr[i]!=arr[t]){
			alter=1;
			i++;
			t++;}
		
		else{
			alter=0;
			i++;
			t++;}
		}	
	
	if (alter==1)
		printf ("\n El número sí es alternante");
	else
		printf ("\n El número no es alternante");
		
		i=0;    // I did this to see if it detection of even or odds worked right
		while (i<cont){
			printf ("\n %i (0=par, 1=impar)", arr[i]);
			i++;
		}			
}

The problem is that in this part:

Code:

while (i<cont){
		if (dig%2==0){
		arr[i]=0;
		i++;
		temp=temp/10;
		dig=temp%10;}
		
		else if (dig%2!=0){
			arr[i]=1;
			i++;
			temp=temp/10;
			dig=temp%10;}
		}

The first digit to enter will always be taken as an even one, and I don't know why.

Because when you do dig = temp%10, temp is 0, and 0%10 is 0, which coincidentally is even.

Thanks.