How Can Numbers Be Printed Sequentially from 1 to 1000 Without Loops or Conditional Statements in C?

Solving the Enigma of Printing Numbers without Loops or Conditionals

The challenge of printing numbers sequentially from 1 to 1000 without relying on loop or conditional constructs intrigues programmers with its unconventional approach. How can such a seemingly straightforward task be accomplished without the fundamental tools of programming?

Unlocking the Solution in C

The solution, as demonstrated in the C code snippet below, lies in exploiting pointer arithmetic and recursion.

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

void main(int j) {
  printf("%d\n", j);
  (&&main + (&exit - &main)*(j/1000))(j+1);
}

This code ingeniously utilizes function pointers and recursion to avoid the need for loops or conditionals. It calculates the address of the next recursive call based on the ratio of j/1000. By carefully manipulating the address of the main function, the program effectively simulates a "jump" to the next number in the sequence.

A Variant in Standard C

For those who prefer a more standard C approach, the following code eliminates the reliance on arithmetic on function pointers:

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

void f(int j)
{
    static void (*const ft[2])(int) = { f, exit };

    printf("%d\n", j);
    ft[j/1000](j + 1);
}

int main(int argc, char *argv[])
{
    f(1);
}

Both of these C code snippets demonstrate the possibility of printing numbers sequentially without loops or conditionals. They showcase the power of manipulating function pointers and recursion to overcome the seemingly insurmountable restriction.

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