C语言表示n维数组

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

#define MAX_ARRAY_DIM 8
typedef int ElemType;

typedef struct{
    ElemType *base; // 数组元素基址
    int dim;        // 维度
    int *bounds;    // 数组维界基址
    int *constants; // 数组映像函数常量基址
}array;

void init(array *a, int dim, ...){
    // 判断维数dim和随后的各维度长度是否合法，合法则构建数组
    if (dim <1||dim>MAX_ARRAY_DIM) exit(1); // error
    a->dim = dim;
    a->bounds = malloc(a->dim*sizeof(int));
    if(!a->bounds) exit(1);  // malloc memory error
    // 若各维度长度合法，则存入a->bounds,并求出a中的元素总数
    int elemTotal = 1;
    va_list ap;
    va_start(ap, dim);
    for (int i=0; i<a->dim; ++i){
        a->bounds[i] = va_arg(ap, int);
        if (a->bounds[i]<0) return exit(1); //can't assign negative values
        elemTotal *= a->bounds[i];
    }
    va_end(ap);
    a->base = malloc(elemTotal*sizeof(ElemType));
    if (!a->base) exit(1); // allocte memory failure, then exit
    // 下一步则是求映像函数常数，以简化计算
    a->constants = malloc(dim*sizeof(ElemType));
    if (!a->constants) exit(1); // error
    a->constants[dim-1] = 1;
    for (int i=dim-2; i>=0; --i){
        a->constants[i] = a->bounds[i+1]*a->constants[i+1];
    }
}

void destory(array *a){
    if !(a->base) exit(1);  // empty
    free(a->base);
    if !(a->bounds) exit(1);
    free(a->bounds);
    if !(a->constants) exit(1);
    free(a->constants);
}

void locate(array a, va_list ap, int *off){
    // 若ap指示的下标合法，则求出该元素在a中的相对地址off
    *off = 0;
    for (int i=0; i<a->dim; ++i){
        int ind = va_arg(ap, int);
        if (ind <0|| ind>=a->bounds[i]) exit(1); // excess
        off += a->constants[i]*ind;
    }
}


void main(){
    array a;
    init(&a, 3, 4, 4, 4);
}