A past puzzle — fully playable. 4 attempts, hints on wrong guesses.
stdle-69.c
1#include<stdio.h>
2intmain(void){
3chara='a';
4charb=a-32;
5printf("%c%c\n",a,b);
6return0;
7}
Numbers
Answer & explanation
Console output
aA
Why
The char 'a' (97) is promoted to int for the subtraction, giving the int 65, which is then converted back to char b. 65 is the code for 'A', so %c prints 'a' then 'A'. This is the classic ASCII case-flip, and it relies on promotion to int for the arithmetic step.