From 6cb3230d278a57c705de40d608d4bcd776156193 Mon Sep 17 00:00:00 2001
From: Wesley Moore <wes@wezm.net>
Date: Sat, 7 Dec 2019 14:44:38 +1100
Subject: [PATCH] Day 5 part 2

---
 2019/src/computer.rs | 50 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/2019/src/computer.rs b/2019/src/computer.rs
index 870a676..7994982 100644
--- a/2019/src/computer.rs
+++ b/2019/src/computer.rs
@@ -10,6 +10,10 @@ enum Instruction {
     Multiply(Mode, Mode),
     Input,
     Output(Mode),
+    JumpIfTrue(Mode, Mode),
+    JumpIfFalse(Mode, Mode),
+    LessThan(Mode, Mode),
+    Equals(Mode, Mode),
     Halt,
 }
 
@@ -41,6 +45,22 @@ fn decode(mut instruction: i32) -> Instruction {
         ),
         3 => Instruction::Input,
         4 => Instruction::Output(Mode::from(divmod(&mut instruction, 10))),
+        5 => Instruction::JumpIfTrue(
+            Mode::from(divmod(&mut instruction, 10)),
+            Mode::from(divmod(&mut instruction, 10)),
+        ),
+        6 => Instruction::JumpIfFalse(
+            Mode::from(divmod(&mut instruction, 10)),
+            Mode::from(divmod(&mut instruction, 10)),
+        ),
+        7 => Instruction::LessThan(
+            Mode::from(divmod(&mut instruction, 10)),
+            Mode::from(divmod(&mut instruction, 10)),
+        ),
+        8 => Instruction::Equals(
+            Mode::from(divmod(&mut instruction, 10)),
+            Mode::from(divmod(&mut instruction, 10)),
+        ),
         99 => Instruction::Halt,
         _ => panic!("Invalid opcode: {}", opcode),
     }
@@ -101,6 +121,36 @@ impl<'a> Memory<'a> {
                     println!("{}", value);
                     ip += 2;
                 }
+                Instruction::JumpIfTrue(mode1, mode2) => {
+                    if self.read(ip + 1, mode1) != 0 {
+                        ip = self.read(ip + 2, mode2);
+                    } else {
+                        ip += 3;
+                    }
+                }
+                Instruction::JumpIfFalse(mode1, mode2) => {
+                    if self.read(ip + 1, mode1) == 0 {
+                        ip = self.read(ip + 2, mode2);
+                    } else {
+                        ip += 3;
+                    }
+                }
+                Instruction::LessThan(mode1, mode2) => {
+                    if self.read(ip + 1, mode1) < self.read(ip + 2, mode2) {
+                        self.write(self.read(ip + 3, Mode::Immediate), 1);
+                    } else {
+                        self.write(self.read(ip + 3, Mode::Immediate), 0);
+                    }
+                    ip += 4;
+                }
+                Instruction::Equals(mode1, mode2) => {
+                    if self.read(ip + 1, mode1) == self.read(ip + 2, mode2) {
+                        self.write(self.read(ip + 3, Mode::Immediate), 1);
+                    } else {
+                        self.write(self.read(ip + 3, Mode::Immediate), 0);
+                    }
+                    ip += 4;
+                }
                 Instruction::Halt => break,
             }
         }