How to Pass multiple arrays from a function into main? - c

Question

Im not used to using pointers or coding in C. I've created a void function in which I defined a couple arrays and populated them using my Input parameters. Now I need to use these arrays in my main but unsure on how to call them. Following is my function code :
void showCDF(int Integer_Array[], int length){ //Calculates the CDF and stores it in "y_values"
int i = 1; // i initialized at 1
int y_axis[20];
int size_of_x = Integer_Array[length-1]- Integer_Array[0]+1; // size of x is the difference between the first and
int x_axis[size_of_x]; // last element of input array.
x_axis[0] = Integer_Array[0]; // first element of x is the first element of input array
//printf("%d ", x_axis[0]); // print out the first element
while (x_axis[i-1]<Integer_Array[length-1]){ // while previous element of x < last element of Input
x_axis[i]= x_axis[i-1] + 1; // adding the previous value of x to 1 store as this value
//printf("%d ", x_axis[i]); // print out all consecutive elements of x
i +=1;
}
printf("\n");
for (i=0;i<21;i++){
y_axis[i] = 5*i;
//printf("%d \n",y_axis[i]);
}
int y_values[size_of_x + 1]; // size of y is dependant on the size of x
for (int j=0; j < size_of_x +1 ; j++){
float n = 0; // Count to show total, initialized at 0
int i= 0;
while (x_axis[j] >= Integer_Array[i] && i<length){ // While x at j is greater than or equal to values of
n ++; // Integer_array at i, AND i is less than length.
i ++; // Then increase the count and i
} // else:
y_values[j]=(n/length)*100; // Then corresponding y at j= % of n / length (or the cdf)
//printf( "%d ", y_values[j]); // print out the cdf
}
}
In my main Im calling my function and variables y_axis, y_value, x_axis like this:
int y_axis[20];
showCDF(integerArray, NUMBER_ENTRIES);
for (i=0;i<21;i++){
printf("%d \n", y_axis[i]);
}
But this just gives me a gibberish number like:
0
0
0
0
0
0
0
0
0
0
0
0
1
0
4199677
0
0
0
0
0
825307441
Any help would be appreciated!