advent-of-code

commit c70021f79022a907ac687d7ea5ee8ec4705413e9
parent dcac2c32d51762c729f68004e2c021c4617f81bc
Author: Shimmy Xu <shimmy.xu@shimmy1996.com>
Date:   Mon,  2 Dec 2019 00:40:22 -0500

Add Rust solution for day 2

Diffstat:
A
day-02/Makefile
 | 
13
+++++++++++++
A
day-02/day-02.rs
 | 
52
++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/day-02/Makefile b/day-02/Makefile
@@ -0,0 +1,13 @@
+CC := g++
+CCFLAGS := --std=c++17 -Wall
+
+all: day-02-cpp day-02-rust day-02.jl
+	julia day-02.jl
+	./day-02-cpp
+	./day-02-rust
+
+day-02-cpp: day-02.cc
+	$(CC) $(CCFLAGS) $^ -o $@
+
+day-02-rust: day-02.rs
+	rustc $^ -o $@
diff --git a/day-02/day-02.rs b/day-02/day-02.rs
@@ -0,0 +1,52 @@
+fn main() {
+    let input = std::fs::read_to_string("input.txt")
+        .unwrap()
+        .trim()
+        .split(",")
+        .map(|op| op.parse::<usize>().unwrap())
+        .collect::<Vec<usize>>();
+    println!("Rust:");
+    println!("Part 1: {}", part_1(&input));
+    println!("Part 2: {}", part_2(&input));
+}
+
+fn computer(input: &Vec<usize>, noun: usize, verb: usize) -> usize {
+    let mut input: Vec<usize> = input.clone();
+    input[1] = noun;
+    input[2] = verb;
+
+    let mut pc = 0;
+    loop {
+        match input[pc] {
+            1 => {
+                let res_loc = input[pc + 3];
+                input[res_loc] = input[input[pc + 1]] + input[input[pc + 2]];
+                pc += 4;
+            }
+            2 => {
+                let res_loc = input[pc + 3];
+                input[res_loc] = input[input[pc + 1]] * input[input[pc + 2]];
+                pc += 4;
+            }
+            99 => break,
+            _ => {}
+        }
+    }
+
+    input[0]
+}
+
+fn part_1(input: &Vec<usize>) -> usize {
+    computer(&input, 12, 2)
+}
+
+fn part_2(input: &Vec<usize>) -> usize {
+    for noun in 0..=99 {
+        for verb in 0..=99 {
+            if computer(&input, noun, verb) == 19690720 {
+                return noun * 100 + verb;
+            }
+        }
+    }
+    0
+}