using System;
using System.Text;
// 7H15 M3554G3 is written in leet speak, where numbers resemble letters.
// place each leetspeak character with its matching letter
// (7 -> T, 1 -> I, 5 -> S, 3 -> E) and build a new string
// 7H15 -> THIS | M3554G3 -> MESSAGE
// Your brain can interpret distorted or number‑substituted letters
// surprisingly well because it recognizes the overall word
// shapes and patterns, not just individual characters.
class LeetDecoder
{
// ------------------------------------------------------------
// Convert a single leet character into a normal alphabet letter
// ------------------------------------------------------------
static char DecodeChar(char c) {
return c switch
{
'7' => 'T',
'1' => 'I',
'5' => 'S',
'3' => 'E',
'4' => 'A',
'0' => 'O',
_ => c // keep letters like H, M, G, etc.
};
}
// ------------------------------------------------------------
// Convert an entire string from leet speak to normal text
// ------------------------------------------------------------
static string DecodeLeet(string s) {
StringBuilder sb = new StringBuilder(s.Length);
foreach (char c in s)
sb.Append(DecodeChar(c));
return sb.ToString();
}
static void Main()
{
// Test lines provided by the user
string[] lines =
{
"7H15 M3554G3",
"53RV35 7O PR0V3",
"H0W 0UR M1ND5 C4N",
"D0 4M4Z1NG 7H1NG5!",
"1MPR3551V3 7H1NG5!",
"1N 7H3 B3G1NN1NG",
"17 WA5 H4RD BU7",
"N0W, Y0UR M1ND 1S",
"R34D1NG 17",
"4U70M471C4LLY."
};
// Decode and print each line
foreach (string line in lines)
Console.WriteLine(DecodeLeet(line));
}
}
/*
run:
THIS MESSAGE
SERVES TO PROVE
HOW OUR MINDS CAN
DO AMAZING THINGS!
IMPRESSIVE THINGS!
IN THE BEGINNING
IT WAS HARD BUT
NOW, YOUR MIND IS
READING IT
AUTOMATICALLY.
*/
