#include <stdio.h>
#include <stdlib.h>
int adding (int a[], int);
int summing (int*, int);

int adding (int a[], int n) {
	int i, sum = 0;

	for (i = 0; i < n; i++) sum += a[i];

	return sum;
}
int summing (int* a, int n) {
	int sum = 0;
	while (n-- > 0) {
//		sum += *a++;		// output is 6 6
		sum += (*a)++;		// output is 10 6   why is adding now wrong?
//		sum += *(a++);		// output is 6 6
		printf (" sum = %d", sum);
	}

	return sum;
}

void main (void) {

	int b[10] = {0,1,2,3,4, 5,6,7,8,9};
	int i;

	printf ("\nAdding = %d Summing = %d", adding (b, 4), summing (&b[0], 4));
	for (i=0; i<9; i++)
		printf("\n%d", b[i]);
	printf ("\nAdding = %d", adding (b, 4));
	printf ("\nAdding = %d\n", adding (b, 4));
	printf ("\nSumming = %d", summing (b, 4));
	
	for (i=0; i<9; i++)
		printf("\n%d", b[i]);

}

// Read King P. 226 or
// Read K&R P. 95
// Output on Mac with Metrowerks C/C++ is:
// Adding = 10 Summing = 6		Why is the output from adding not 6?
// Adding = 10
// Summing = 22			Why is the output from summing now 22?
// If parameters are copied into functions, why are all the outputs not 6?


// The output from the gnu C compiler is:
// Adding = 6 Summing = 6
// Adding = 10
// Summing = 22

// Output from PC with Borland C/C++ compiler is:

// Current array:  0  1  2  3  4  5  6  7  8  9
// 
//  in summing()...  n=3:sum= 0  n=2:sum= 1  n=1:sum= 3  n=0:sum= 6
// 
//  in adding()...  i=0:sum= 4  i=1:sum= 5  i=2:sum= 7  i=3:sum= 10
// 
// Adding = 10 Summing = 6
// 
// Current array:  4  1  2  3  4  5  6  7  8  9
// 
//  in adding()...  i=0:sum= 4  i=1:sum= 5  i=2:sum= 7  i=3:sum= 10
// 
// Adding = 10
// 
// Current array:  4  1  2  3  4  5  6  7  8  9
// 
//  in summing()...  n=3:sum= 4  n=2:sum= 9  n=1:sum= 15  n=0:sum= 22
// 
// Summing = 22
// 
// Current array:  8  1  2  3  4  5  6  7  8  9
// 
// If still in doubt then intitialize
// int b[] = {0, 2, 4, 6, 8, 10, 12, 14, 16, 18};