多維數組的順序表示

多維數組節點，有四個元素
struct array 
{
        int *base;            //存放數組的元素的基地址
        int dim;               //表示多維數組的維數
        int *bounds;       //表示每一維的長度
        int *constants;   //存放數組映象函數常量基址

};

 

譬如一個2*3的二維數組，dim就等於二，行優先存儲，bounds[0]就爲2，bounds[1]就爲3。

對於constants，constant[i]就是第i+1層的數組中每一元素(數組)的大小。
對於行主序的2*3的二維數組來說，constant[1]就是每一行的一個元素(如:((a,b,c),(d,e,f))中a,f)佔據的內存長度
constant[0]就是當前行每一列(如:(A,B),其中A=(a,b,c),B=(d,e,f)),A、B佔據的內存長度。

/*
多維數組的順序表示
調試環境：vs2010,gcc
*/

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <malloc.h>

#define	OK		1
#define	ERROR	0
#define	MAX_ARRAY_DIM 8

typedef struct  
{
	int *base;		//數組的基地址，初始化時分配
	int dim;			//數組的維數
	int *bounds;		//數組每一維的長度
	int *constants;	//數組映象函數常量基址

}array;

int init_array(array *a, int dim, ...)
{
	int i = 0;
	int elem_num = 1;		//記錄數組中元素的個數
	va_list ap = NULL;

	if(dim < 1 || dim > MAX_ARRAY_DIM)
	{
		return ERROR;
	}
	a->dim = dim;
	a->bounds = (int *)malloc(dim * sizeof(int));
	if(!(a->bounds))
	{
		return ERROR;
	}

	va_start(ap, dim);
	for(i = 0; i < dim; i++)
	{
		a->bounds[i] = va_arg(ap, int);
		if(a->bounds[i] < 0)
		{
			return ERROR;
		}
		elem_num *= a->bounds[i];
	}
	va_end(ap);

	a->base = (int *)malloc(elem_num * sizeof(int));
	if(! (a->base))
	{
		return ERROR;
	}

	a->constants = (int *)malloc(dim * sizeof(int));
	if(!(a->constants))
	{
		return ERROR;
	}
	a->constants[dim - 1] = 1;
	for(i=dim-2; i>=0; i--)
	{
		a->constants[i] = a->constants[i+1] * a->bounds[i+1];	
	}

	return OK;
}

int destory_array(array *a)
{
	if(a->base)
	{
		free(a->base);
		a->base = NULL;
	}
	else
		return ERROR;

	if(a->bounds)
	{
		free(a->bounds);
		a->bounds = NULL;
	}
	else
		return ERROR;

	if(a->constants)
	{
		free(a->constants);
		a->constants = NULL;
	}
	else
		return ERROR;

	return OK;
}

/*尋找待搜索的arr[i][j][k]相對於基地址的偏移量*/
int locate_array_elem(array a, va_list ap, int *offset)
{
	int i = 0;
	int curdim = 0;

	for(i = 0; i < a.dim; i++)
	{
		curdim = va_arg(ap, int);
		if(curdim < 0 || curdim >=a.bounds[i])
		{
			return ERROR;
		}
		*offset += a.constants[i] * curdim;
	}

	return OK;
}

int get_array_elem(int *e, array a, ...)
{
	va_list ap;
	int result = 0;
	int offset = 0;
	
	va_start(ap, a);
	if(!(result = locate_array_elem(a, ap, &offset)))
	{
		return ERROR;
	}
	va_end(ap);

	*e = *(a.base + offset);

	return OK;
}

int assign_array_elem(int e, array *a, ...)
{
	va_list ap;
	int result = 0;
	int offset = 0;
	va_start(ap, a);
	if(!(result = locate_array_elem(*a, ap, &offset)))
	{
		return ERROR;
	}
	va_end(ap);
	
	*(a->base + offset) = e;

	return OK;
}


int main(int argc, char *argv[])
{
	array arr;
	int dim = 3;
	int bound1 = 2, bound2 = 3, bound3 = 4;	//arr[2][3][4]數組
	int i = 0, j = 0, k = 0;
	int assign_elem = 0;
	int get_elem = 0;
	int *p = NULL;

	init_array(&arr, dim, bound1, bound2, bound3);

	printf("array.bounds = ");			//順序輸出array.bounds
	p = arr.bounds;
	for(i = 0; i < dim; i++)
	{
		printf("%d ", *(p + i));
	}

	printf("\narray.contents = ");		//順序輸出array.contents
	p = arr.constants;
	for(i = 0; i < dim; i++)
	{
		printf("%d ", *(p + i));
	}

	printf("\narray[%d][%d][%d] : \n", bound1, bound2, bound3);
	for(i = 0; i < bound1; i++)
	{
		for(j = 0; j < bound2; j++)
		{
			for(k = 0; k < bound3; k++)
			{
				assign_elem = i * 100 + j * 10 + k;
				assign_array_elem(assign_elem, &arr, i, j, k);
				get_array_elem(&get_elem, arr, i, j, k);
				printf("array[%d][%d][%d]=%-4d", i, j, k, get_elem);
			}
			printf("\n");
		}
		printf("\n");
	}

	p = arr.base;
	for(i = 0; i < bound1 * bound2 * bound3; i++)
	{
		printf("%-4d", *(p + i));
		if(i % (bound2 * bound3) == bound2 * bound3 - 1)
		{
			printf("\n");
		}
	}

	destory_array(&arr);
	
	return 0;
}