Problem using pointers

[apeachaday]

I have a small issue with my code. My instructor provided the main and we are to write the functions. I have most of my code functional, but he has thrown me for a bit of loop in one section. I don't understand what he has done with the table_min function. I don't understand how that line of code is supposed to work. The original instructions stated:

7. Write table_min a function to find the smallest value in an array.
int table_min (array , size);

If I take my code out, it will calculate the average, but when I put it into what he has, I get very long, long lines of cryptic errors. I appreciate any help or tips provided. Again, Thanks in advance for your time!!!

#include <iostream>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <cstdlib>

using namespace std;

//**********Function Prototypes**********
void table_fill(int *, int, int);
void table_print(int *, int);
void table_add1(int *, int);
void table_print_rev(int *, int);
void table_min(int *, int);
//********End Function Prototypes********

int main()
{
    const int Max = 20;
    int ary[Max];
    int bry[Max];
    int *p, *s, *tp;

    p = &ary[0];
    s = &bry[0];

    table_fill( p, Max, 20 );
    cout << endl << "Fill array with 20s " << endl;
    table_print( p, Max );  cout << endl << endl;

    cout << endl << "Add 1 to first 10 elements " << endl;
    table_add1( p, 10);
    table_print( p, Max );  cout << endl << endl;

    tp = s;   // save pointer
    for (int i=1; i<= Max; i++ )
    {
	table_fill( s, 1, i );
	s++;
    }
    cout << endl << "Fill array with 1 to 20 " << endl;
    s = tp;   // restore pointer
    table_print( s, Max );  cout << endl << endl;

    cout << endl << "Print reverse order " << endl;
    table_print_rev( s, Max );  cout << endl << endl;

    table_fill( p, Max, 0 );
    cout << endl << "Zero out array " << endl;
    table_print( p, Max );  cout << endl << endl;

    s = tp;        // What's happening here?
    for ( int i=Max; i>=0; i--)
    {
	   table_add1( s, i );
    }

    cout << endl << "Fill array with ???? " << endl;
    table_print( s, Max );  cout << endl << endl;

    cout << endl << "Print reverse order " << endl;
    table_print_rev( s, Max );  cout << endl << endl;

    for (int i=0; i<Max/2; i++)
    {
	    tp = p+10+i;
	    table_fill( tp, 1, i*2 );
	    tp = p+10-i;
	    table_fill( tp, 1, i*3 );
    }
    cout << endl << "Fill array with <-> " << endl;
    tp = p + 1;
    table_print( p, Max );  cout << endl << endl;

//*******Issues Begin Here********
//I don't understand how this works.
    cout << endl << "Min for previous table " << table_min( p, 12 );

    return 0;
}

//**********Function Definitions**********
void  table_fill(int *ptr, int M, int val)
{
    //Fill the Array
    for(int i = 0; i < M; i++)
    {
        *ptr = val;
        ptr++;
    }
}

void table_print(int *ptr, int M)
{
    //Print the Table
    for(int i = 0; i < M; i++)
    {
        cout << *ptr << " ";
        ptr++;
    }
}

void table_add1(int *ptr, int val)
{
    //Add 1 to the first 10 elements of the array
    for(int i = 0; i < val; i++)
    {
        *ptr = *ptr + 1;
        ptr++;
    }
}

void table_print_rev(int *ptr, int M)
{
    //Print Array in Reverse
    for(int i = 0; i < 20; i++)
    {
        cout << *(ptr + 19) << " ";
        ptr--;
    }
}

void table_min(int *ptr, int val)
{

    int smallest = *ptr;

    for(int i = 0; i < val; i++)
    {
        if(*ptr <= smallest)
        {
            smallest = *ptr;
        }
        ptr++;
    }
}
//********End Function Definitions********

[vlad from moscow]

The statement

cout << endl << "Min for previous table " << table_min( p, 12 );

is incorrect because your function table_min does not return a value. Its return type is defined as void

It is better to define your function as follows

int table_min( int *a, int n )
{
    int min = a[0];

    for( int i = 1; i < n; i++ )
    {
        if ( a[i] < min ) min = a[i];
    }

    return ( min );
}

[apeachaday]

Thanks so much for your help. I made the corrections and it works perfectly.