Write and explain the output of following c++ code.

Question

typedef char STRING[80];
void MIXITNOW(STRING S)
{
int Size=strlen(S);
for(int I=0;I<Size–1;I+=2)
{
char WS=S[I];
S[I]=S[I+1];
S[I+1]=WS;
}
for(I=1;I<Size;I+=2)
if(S[I]>=’M’ && S[I]<=’U’)
S[I]=’@’;
}
void main()
{
STRING Word=”CRACKAJACK”;
MIXITNOW(Word);
cout<<Word<<endl;
}

Answer 1

hi,
the above program swap the character
like this
CRACKAJACK
RCCAAKAJKC
then it will check the character whether it is greater than M and less than U.
if it so then it will replace with @ symbol

Answer 2

wonder why you use array of char instead single string ?
string itself is array of char.

use it per char by SubString.

by the way index are :
C is 0
R is 1
A is 2
C is 3
K is 4
A is 5
J is 6
A is 7
C is 8
K is 9

during loop i=0 to (9-1) , you stepped 2 per loop ,
means : 0 , 2 , 4 , 6 , 8
C A K J C are inside WS simultanously ,
in your S you shifted or swaped current
0 , 2 , 4 , 6 , 8 with 1 , 3 , 5 , 7 , 9 by puting WS in S.
so it will be :
C _ A _ K _ J _ C _ + R _ C _ A _ A _ K =
R <-> C
C <-> A
A <-> K
A <-> J
K <-> C
still CRACKAJACK , confusing , but well..

your conditional if(S[I]>=’M’ && S[I]<=’U’) S[I]=’@’; }
never runs , because the position between 'M' and 'U' need to be declared or converted to ascii first then you can replace R with '@'.