commit c979478938286953220ca340f235d4fb3567ff2c
Author: datalore <d4t4.l0r3@protonmail.ch>
Date:   Tue Oct 24 13:14:21 2023 +0200

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1f7b034
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+brute
+shift
+count
+vigenere
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..e7565c5
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+all: shift brute count vigenere
+shift: shift.cc
+	g++ shift.cc -o shift
+brute: brute.cc
+	g++ brute.cc -o brute
+count: count.cc
+	g++ count.cc -o count -std=c++20
+vigenere: vigenere.cc
+	g++ vigenere.cc -o vigenere
+clean:
+	rm shift brute
diff --git a/brute.cc b/brute.cc
new file mode 100644
index 0000000..9a8a8c3
--- /dev/null
+++ b/brute.cc
@@ -0,0 +1,27 @@
+#include <iostream>
+
+void shift(char* text, int key)
+{
+	std::cout << key << ": ";
+	for(int i = 0; text[i] != 0; ++i)
+	{
+		char c = text[i]-key;
+		if(c < 'a') c+=26;
+		if(c > 'z') c-=26;
+		std::cout << c;
+	}
+	std::cout << std::endl;
+}
+int main(int argc, char** argv)
+{
+	if(argc < 2)
+	{
+		std::cout << "Usage: " << argv[0] << " <ciphertext>" << std::endl;
+		return 0;
+	}
+	for(int i = 1; i < 26; ++i)
+	{
+		shift(argv[1], i);
+	}
+	return 0;
+}
diff --git a/count.cc b/count.cc
new file mode 100644
index 0000000..24fccd7
--- /dev/null
+++ b/count.cc
@@ -0,0 +1,30 @@
+#include <map>
+#include <iostream>
+
+int main(int argc, char** argv)
+{
+	if(argc < 2)
+	{
+		std::cout << "Usage: " << argv[0] << " <ciphertext>" << std::endl;
+		return 0;
+	}
+	char* ciphertext = argv[1];
+	std::map<char, int> letters;
+
+	for(int i = 0; ciphertext[i] != 0; ++i)
+	{
+		if(letters.contains(ciphertext[i]))
+		{
+			letters[ciphertext[i]]++;
+		}
+		else
+		{
+			letters[ciphertext[i]] = 1;
+		}
+	}
+	for(auto& [key, value] : letters)
+	{
+		std::cout << key << ": " << value << std::endl;
+	}
+	return 0;
+}
diff --git a/shift.cc b/shift.cc
new file mode 100644
index 0000000..1c4d859
--- /dev/null
+++ b/shift.cc
@@ -0,0 +1,24 @@
+#include <iostream>
+
+int main(int argc, char** argv)
+{
+	char* text;
+	int key;
+	if(argc < 3)
+	{
+		std::cout << "Usage: " << argv[0] << " <plain text> <key>" << std::endl;
+		return 0;
+	}
+	text = argv[1];
+	key = atoi(argv[2]);
+	
+	for(int i = 0; text[i] != 0; ++i)
+	{
+		char c = text[i]+key;
+		if(c < 'a') c+=26;
+		if(c > 'z') c-=26;
+		std::cout << c;
+	}
+	std::cout << std::endl;
+	return 0;
+}
diff --git a/vigenere.cc b/vigenere.cc
new file mode 100644
index 0000000..2c3b229
--- /dev/null
+++ b/vigenere.cc
@@ -0,0 +1,31 @@
+#include <iostream>
+
+int keyvalue(char c)
+{
+	return c - 'a';
+}
+int main(int argc, char** argv)
+{
+	char* text;
+	char* key;
+	if(argc < 3)
+	{
+		std::cout << "Usage: " << argv[0] << " <plain text> <key>" << std::endl;
+		return 0;
+	}
+
+	text = argv[1];
+	key = argv[2];
+
+	int ki = 0;
+	for(int pi = 0; text[pi] != 0; ++pi)
+	{
+		char c = text[pi] + keyvalue(key[ki]);
+		if(c < 'a') c+=26;
+		if(c > 'z') c-=26;
+		std::cout << c;
+		if(key[++ki] == 0) ki = 0;
+	}
+	std::cout << std::endl;
+	return 0;
+}