From Newsgroup: comp.lang.c++

// The pseudo code shown below has been converted
// to C compiled as C++
// the pseudo code is easier to read.
// the C code is fully operational.

/***
As I first published here back in 2004:
On 6/23/2004 9:34 PM, Olcott wrote:

function LoopIfYouSayItHalts (bool YouSayItHalts):
if YouSayItHalts () then
while true do {}
else
return false;

Does this program Halt?

(Your (YES or NO) answer is to be considered
translated to Boolean as the function's input
parameter)

Please ONLY PROVIDE CORRECT ANSWERS!

***/

#include <stdio.h>
#include <conio.h>

void LoopIfYouSayItHalts(bool YouSayItHalts)
{
if (YouSayItHalts)
while(true)
;
else
return;
}

void OutputProgram()
{
printf("\n\n\nvoid LoopIfYouSayItHalts "
"(bool YouSayItHalts)\n");
printf("{\n");
printf(" if (YouSayItHalts)\n");
printf(" while(true)\n");
printf(" ;\n");
printf(" else\n");
printf(" return;\n");
printf("}\n\n\n");
}

void Prompt()
{
char choice = 'x';
printf("Does this program Halt?\n");
printf("(Y or N) translated to Boolean argument"
" to LoopIfYouSayItHalts()\n");
printf("\nPlease ONLY PROVIDE CORRECT (Y or N) ANSWERS!\n");
while (choice != 'Y'&& choice != 'y' &&
choice != 'N' && choice != 'n')
{
choice = getch();
if (choice != 'Y'&& choice != 'y' &&
choice != 'N' && choice != 'n')
printf("Must be (Y or N)\n");
}

if (choice == 'Y' || choice == 'y')
{
printf("\nWrong Answer!\n"
"LoopIfYouSayItHalts(true) is stuck in a loop!\n\n");
LoopIfYouSayItHalts(true);
}
if (choice == 'N' || choice == 'n')
{
printf("\nWrong Answer!\n"
"LoopIfYouSayItHalts(false) halts now!\n\n");
LoopIfYouSayItHalts(false);
}
}


int main()
{
OutputProgram();
Prompt();
return 0;
}
--
Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer

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