Thread: Help! 2D arrays, maximum and average. Problem calling the function. (in C)

I have a 2D array with random generated values and some defines -1 values. I need to find the maximum and average values of the array. Only for the values that are >-1.

I created a for loop function for this, but i'm lost in calling it in main(), i don't know if i should set parameters for the maxavg().

Since i'm a beginner i'm really lost trying to fix this, any help?

Code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h> 
#include <limits.h>

int GetRand(int min, int max);
int maxavg();

int main ()
{
    int a[21][21], i , j, average, maximum, ret;


    for (i = 0; i < 21; i++)
    {
        for ( j = 0; j < 21; j++)
        {
            a[i][j] = GetRand(0, 100);
        
            printf("%3d" , a[i][j]);
        }
        
            a[2][15] = -1;
            a[10][6] = -1;
            a[13][5] = -1;
            a[15][17] = -1;
            a[17][17] = -1;
            a[19][6] = -1;
    
        printf("\n");
        
    }
    
    
    average = ;
    maximum = ;    
    
    printf("average = %d \n maximum = %d", average, maximum);
    
    
    
    
    return 0;

}



// random seed
    int GetRand(int min, int max);
    int get () 
    {
      int i, r;
    for (i = 0; i < 21; i++)
 {
        r = GetRand(0, 100);
        printf("Your number is %d \n", r);
     }
 return(0);
 }

int GetRand(int min, int max)
{
    static int Init = 0;
    int rc;                

    if (Init == 0)
    {
        srand(time(NULL));
        Init = 1;
    }

    rc = (rand() % (max - min +1) +min);

    return (rc);
}




// max and average
    
    int maxavg();
    {
        
    int max=INT_MIN, sum=0, count=0, avg, n, m, current;
    
    current = a[i][j];
    avg = sum/count;
    
    for(n = 0; n < 21; n++){
        for(m =0; m < 21; m++){
            if(current > -1){
                sum = sum + current;
                count = count + 1;
                if(current > max){
                    max = current;
                }
            }
            
        }
    }
    
    
    return(0);
    
}

ok so the first thing you need to realize is that you can't use a variable or any data type (including your array) outside the scope it's declared in.
the scope is those curly braces every function has:

Code:

function1(){
    int a = 1;
}

function2(){
    int b = 2;
    b += a ;   //this won't work
}

What you need to do is this:

Code:

int function1(){ // note the function is type int because we are returning a which is also an int
    int a = 1;
    return a;
}

void function2(){
    int b = 2;
    b += function1(); 
    
}

honestly I'm not a very good teacher so it's best you watch these series the guy explains things very clearly im on vid 45
https://www.youtube.com/watch?v=sFZD...4AMPJq&index=3