ダディクールがC/C++の宿題を片づけます 32代目

>>861 かなり本気で渦巻きを書いてみた
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char* pos(char* data, int x, int y, int width){  return data + (width + 1) * y + x;}
int main(void){
  int size, x = 0, y = 0, i;
  char *matrix;
  scanf("%d", &size);
  matrix = (char*)malloc(sizeof(char) * (size + 1) * size);
  memset(matrix, ' ', sizeof(char) * (size + 1) * size);
  for (i = 0; i < size; ++i) *pos(matrix, size, i, size) = 0;
  *pos(matrix, x, y, size) = '*';
  for(; ; ) {
    while (++x < size && *pos(matrix, x, y, size) == ' ') *pos(matrix, x, y, size) = '-';
    *pos(matrix, --x, y, size) = '*';
    if (*pos(matrix, x, y + 1, size) != ' ') goto exit_loop;
    while (++y < size && *pos(matrix, x, y, size) == ' ') *pos(matrix, x, y, size) = '|';
    *pos(matrix, x, --y, size) = '*';
    if (*pos(matrix, x - 1, y, size) != ' ') goto exit_loop;
    while (--x < size && *pos(matrix, x, y, size) == ' ') *pos(matrix, x, y, size) = '-';
    *pos(matrix, ++x, y, size) = '*';
    if (*pos(matrix, x, y - 1, size) != ' ') goto exit_loop;
    while (--y < size && *pos(matrix, x, y, size) == ' ') *pos(matrix, x, y, size) = '|';
    *pos(matrix, x, ++y, size) = '*';
    if (*pos(matrix, x + 1, y, size) != ' ') goto exit_loop;
  }
exit_loop:
  for (i = 0; i < size; ++i) printf("%s\n", pos(matrix, 0, i, size));
  free(matrix);
  return 0;
}