//HW5 part a
//Nov 30, 2016

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

int **generatePointerArray(int);

void ascendingSort(int **array, int len, int i);
void descendingSort(int **array, int len, int i);

int main(){
	int i;
	srand(time(NULL));

	int arrayLength = rand()%5+7;

	int array1[arrayLength];								//initialize an array of random length
	int **array2 = generatePointerArray(arrayLength);		//allocates memory for a pointer array
	int **array3 = generatePointerArray(arrayLength);		//allocates memory for a pointer array

	for(i=0; i<arrayLength; i++){							//generates an array of random integers and 2 pointer arrays that point to those values
		array1[i] = rand()%100;
		array2[i] = &array1[i];
		array3[i] = &array1[i];
	}

	ascendingSort(array2, arrayLength, 0);					//sorts the pointer arrays without editing the origional arrays (ascending)
	descendingSort(array3, arrayLength, 0);					//sorts the pointer arrays without editing the origional arrays (descending)

	printf("\tAscending\tOriginal\tDescending\n");			//prints the arrays in a nice format yay
	for(i=0; i<arrayLength; i++){
		printf("\t    %d\t\t   %d\t\t    %d\n", *array2[i], array1[i], *array3[i]);
	}

	free(array2);											//releases the allocated memory
	free(array3);											//releases the allocated memory

	return 0;
}

int **generatePointerArray(int len){						//returns an array of pointers of length 'len'
	int **array = (int**)calloc(len+1, sizeof(int*));
	array[len] = NULL;
	return array;
}

void ascendingSort(int **array, int len, int i){			//selection sort
	int j;
    int *tmp;

    if(array[i] != NULL){
        for(j=i; j<len; j++){
            if(*array[i]>*array[j]){
                tmp = array[i];
                array[i] = array[j];
                array[j] = tmp;
            }
        }
        ascendingSort(array, len, i+1);
    }
}

void descendingSort(int **array, int len, int i){			//insertion sort algorithm
	int j;
	int *tmp1;
	tmp1 = array[i];
	for(j=i-1; j>=0; j--){
		if(*tmp1>*array[j]){
			array[j+1] = array[j];
			if(j==0){
				array[0] = tmp1;
				break;
			}
		}else{
			array[j+1] = tmp1;
			break;
		}
	}
	if(i+1<len){descendingSort(array, len, i+1);}
}