C Program

Question

#include <stdio.h>
char *str[]={"FirstSring","Is","Already","Written"};
char **strp[]={str+3,str+2,str+1,str};
char ***strpp=strp;
int main(void) 
{
        printf("%s",**++strpp);
        printf("%s",*--*++strpp+3);
        return 0;
}

Output of this, and the interpretation?

Comments

finally I have seen one such QS in GO !

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self made ? or other source ?

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Not self made.

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I am getting the output as Already Is.

Answer is given as Already stSring.

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@GateSet i have a small doubt here that when the second printf statement will run than the variable strpp will contain original address or incremented address( i,e incremented by the first printf statement)??

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Exactly my doubt!!

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c compiler is showing "AlreadystSring"

so it means strpp will contain incremented value !!
 

https://www.codechef.com/ide

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Yes. I was doing a minor mistake. Got it!!

Answer 1

#include <stdio.h>

char *str[]={"FirstString","Is","Already","Written"};
// str is an array of char pointers
char **strp[]={str+3,str+2,str+1,str};
// strp is an array of pointers and those pointers point to char
// simply strp is array of pointers
char ***strpp=strp;
// strpp is pointer variable which store address of another pointer

int main(void)  {
		printf("%s",**++strpp); // Already
		
		printf("%s",*--*++strpp+3); //stString

		// (*(--(*(++strpp))))+3 
		// ++ has higher precedence than binary +
		// * has higher precedence than binary +
		// -- has higher precedence than binary +
		
		return 0;
}
// final OP : AlreadystString

Now, Assuming character takes 1 Byte and pointer variable takes 4 Bytes.

1. char *p ; increment on p will take place in $1$ Byte step
2. char **p (Or, any double pointer): increment will take place in $4$ Byte step.

Comments

Sorry I made a typo in "FirstSring".

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@Debashish You are one of many reasons people should use Gateoverflow. Some explanation!!

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Wonderful explanation! :)
BTW which tool you use for drawing these diagrams?