Day 2.1

2019-12-02 20:13:09 +00:00
parent e943794b67
commit de87b93be1
3 changed files with 86 additions and 0 deletions
--- a/02/src/main.zig
+++ b/02/src/main.zig
@@ -0,0 +1,71 @@
+const std = @import("std");
+
+// Load the whole program into memory in one go
+fn loadProgram() anyerror![]u32 {
+    const file = std.io.getStdIn();
+    const stream = &file.inStream().stream;
+    var program = [_]u32{0} ** 1024;
+    var buf = [_]u8{0} ** 255;
+    var i: u32 = 0;
+
+    while (try stream.readUntilDelimiterOrEof(&buf, ',')) |num| {
+        var trimmed = std.mem.trimRight(u8, num, "\r\n");
+        program[i] = try std.fmt.parseInt(u32, trimmed, 10);
+
+        std.debug.warn("{},", program[i]);
+
+        i += 1;
+    }
+
+    std.debug.warn("\n");
+
+    return program[0..program.len];
+}
+
+pub fn main() anyerror!void {
+    var program = try loadProgram();
+
+    // Initial program state.
+    var ip: u32 = 0;
+    var exit: bool = false;
+
+    // Gravity assist modifications
+    program[1] = 12;
+    program[2] = 2;
+
+    while (!exit) {
+        std.debug.warn(" IP {d:4}: ", ip);
+        const opcode = switch (program[ip]) {
+            1 => {
+                var a = program[program[ip + 1]];
+                var b = program[program[ip + 2]];
+                var dest = program[ip + 3];
+                var result = a + b;
+
+                std.debug.warn("ADD:  [{}] + [{}] => {} : {} + {} = {} => {}\n", ip + 1, ip + 2, dest, a, b, result, dest);
+                program[dest] = result;
+                ip += 4;
+            },
+            2 => {
+                var a = program[program[ip + 1]];
+                var b = program[program[ip + 2]];
+                var dest = program[ip + 3];
+                var result = a * b;
+
+                std.debug.warn("MULT: [{}] + [{}] => {} : {} + {} = {} => {}\n", ip + 1, ip + 2, dest, a, b, result, dest);
+                program[dest] = result;
+                ip += 4;
+            },
+            99 => {
+                std.debug.warn("EXIT\n");
+                exit = true;
+            },
+            else => {
+                std.debug.warn("Unknown opcode at IP {}: {}", ip, program[ip]);
+                exit = true;
+            },
+        };
+    }
+
+    std.debug.warn("Part 1: {}\n", program[0]);
+}