Data commit

Task/Vigen-re-cipher/Zig/vigen-re-cipher-1.zig

@@ -0,0 +1,2 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;

Task/Vigen-re-cipher/Zig/vigen-re-cipher-2.zig

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+/// Caller owns the returned slice memory.
+fn vigenere(allocator: Allocator, text: []const u8, key: []const u8, encrypt: bool) Allocator.Error![]u8 {
+    var dynamic_string = std.ArrayList(u8).init(allocator);
+    var key_index: usize = 0;
+    for (text) |letter| {
+        const c = if (std.ascii.isLower(letter)) std.ascii.toUpper(letter) else letter;
+        if (std.ascii.isUpper(c)) {
+            const k = key[key_index];
+            const n = if (encrypt) ((c - 'A') + (k - 'A')) else 26 + c - k;
+            try dynamic_string.append(n % 26 + 'A'); // A-Z
+            key_index += 1;
+            key_index %= key.len;
+        }
+    }
+    return dynamic_string.toOwnedSlice();
+}

Task/Vigen-re-cipher/Zig/vigen-re-cipher-3.zig

@@ -0,0 +1,22 @@
+pub fn main() anyerror!void {
+    // allocator
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer {
+        const ok = gpa.deinit();
+        std.debug.assert(ok == .ok);
+    }
+    const allocator = gpa.allocator();
+    //
+    const stdout = std.io.getStdOut().writer();
+    //
+    const key = "VIGENERECIPHER";
+    const text = "Beware the Jabberwock, my son! The jaws that bite, the claws that catch!";
+
+    const encoded = try vigenere(allocator, text, key, true);
+    defer allocator.free(encoded);
+    _ = try stdout.print("{s}\n", .{encoded});
+
+    const decoded = try vigenere(allocator, encoded, key, false);
+    defer allocator.free(decoded);
+    _ = try stdout.print("{s}\n", .{decoded});
+}