Add '2019/' from commit 'fc21396bc86bc0f706225f4f6e1d8294d344ca53'

git-subtree-dir: 2019
git-subtree-mainline: f1be11fca8
git-subtree-split: fc21396bc8

2019/02/src/main.zig

@@ -0,0 +1,56 @@
+const std = @import("std");
+const intcode = @import("intcode");
+
+fn run(alloc: *std.mem.Allocator, program: []intcode.Word, noun: intcode.Word, verb: intcode.Word) !intcode.Word {
+    program[1] = noun;
+    program[2] = verb;
+
+    var machine = try intcode.Machine.Run(alloc, program);
+    defer machine.deinit();
+
+    return machine.memory[0];
+}
+
+fn runCopy(alloc: *std.mem.Allocator, program: []intcode.Word, noun: intcode.Word, verb: intcode.Word) !intcode.Word {
+    return run(alloc, program, noun, verb);
+}
+
+pub fn main() anyerror!void {
+    var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
+    defer arena.deinit();
+
+    const alloc = &arena.allocator;
+
+    var program = try intcode.loadFromStdIn(alloc);
+
+    // Part 1
+    std.debug.warn("Day 2, Part 1: {}\n", try runCopy(alloc, program, 12, 2));
+
+    // Part 2: 100*100 = 10,000 combinations to try.
+    var memory: []intcode.Word = try alloc.alloc(intcode.Word, program.len);
+    var done: bool = false;
+    var noun: intcode.Word = 0;
+    var verb: intcode.Word = 0;
+
+    std.debug.warn("Day 2, Part 2: ");
+    while (!done) {
+        std.mem.copy(intcode.Word, memory, program);
+        const result = try run(alloc, memory, noun, verb);
+
+        // Too high: 250800 (noun=33, verb=76)
+        if (result == 19690720) {
+            std.debug.warn("noun={} verb={}\n", noun, verb);
+            done = true;
+        }
+
+        noun += 1;
+        if (noun > 100) {
+            noun = 0;
+            verb += 1;
+
+            if (verb > 100) {
+                std.debug.warn("failed!\n");
+            }
+        }
+    }
+}