Code obfuscation doesn't understand
I came across the following code
#include <stdio.h>
int main(void)
{
long long P = 1,E = 2,T = 5,A = 61,L = 251,N = 3659,R = 271173410,G = 1479296389,
x[] = { G * R * E * E * T , P * L * A * N * E * T };
puts((char*)x);
return 0;
}
The thing is, I don't quite understand how it works. This is very confusing to me. Can someone please explain this in detail?
edit: One more thing how to print "Hola mundo!" ("Hello world" in Spanish) the same?
Oh, this is fun. Obviously, you are declaring many variables long long
and one long long
2-cell array . Therefore the array consists of 16 bytes.
Given that each byte is one character ASCII
, the array represents 16 characters (while the latter is probably zero). You can see that:
G * R * E * E * T = 1479296389 * 271173410 * 2 *2 * 5 = 8022916924116329800 =
0x6F57206F6C6C6548
P * L * A * N * E * T = 1 * 251 * 61 * 3659 * 2 * 5 = 560229490 =
0x21646C72
Considering your processor is Little Endian , the in-memory representation of the array is:
48 65 6C 6C 6F 20 57 6F 72 6C 64 21 00 00 00 00
What is Hello World!\x00\x00\x00\x00
ASCII.
Here's the Spanish version:
int main(void)
{
int T=1, E=2, R=2, A=31, Q=784, L=70684, I=6590711, U=1181881,
x[] = { T*I*E*R*R*A, Q*U*E, T*A*L };
puts((char *) x);
return 0;
}