day1 solved

2020/day_1/src/main.rs

@@ -1,3 +1,33 @@
+use std::io::Read;
 fn main() {
-    println!("Hello, world!");
+    let mut file = std::fs::File::open("input1").unwrap();
+    let mut contents = String::new();
+    file.read_to_string(&mut contents).unwrap();
+    let mut v: Vec<i32> = Vec::new();
+    for s in contents.lines() {
+        v.push(s.parse::<i32>().unwrap());
+    }
+    v.sort();
+    let v2 = v.to_vec();
+    for n in v.iter() {
+        for n2 in v2.iter() {
+            let val = n + n2;
+            if val == 2020 {
+                print!("{} + {} = {}\n", n, n2, val);
+                print!("{} * {} = {}\n", n, n2, n * n2);
+            }
+        }
+    }
+    let v3 = v.to_vec();
+    for n in v.iter() {
+        for n2 in v2.iter() {
+            for n3 in v3.iter() {
+                let val = n + n2 + n3;
+                if val == 2020 {
+                    print!("{} + {} + {} = {}\n", n, n2, n3, val);
+                    print!("{} * {} * {} = {}\n", n, n2, n3, n * n2 * n3);
+                }
+            }
+        }
+    }
 }