diff --git a/day1/src/main.rs b/day1/src/main.rs index 1a933b7..b92229f 100644 --- a/day1/src/main.rs +++ b/day1/src/main.rs @@ -27,3 +27,30 @@ fn main() { println!("Fuel 1: {}", fuel_for_modules1(input.clone())); println!("Fuel 2: {}", fuel_for_modules2(input)); } + +#[cfg(test)] +mod day1test { + #[test] + fn example1() { + // Original descriptions: + // > For a mass of 12, divide by 3 and round down to get 4, then subtract 2 to get 2. + // > For a mass of 14, dividing by 3 and rounding down still yields 4, so the fuel required is also 2. + // > For a mass of 1969, the fuel required is 654. + // > For a mass of 100756, the fuel required is 33583. + assert_eq!(super::fuel_for_mass1(12), 2); + assert_eq!(super::fuel_for_mass1(14), 2); + assert_eq!(super::fuel_for_mass1(1969), 654); + assert_eq!(super::fuel_for_mass1(100756), 33583); + } + + #[test] + fn example2() { + // Original descriptions: + // > A module of mass 14 requires 2 fuel. This fuel requires no further fuel (2 divided by 3 and rounded down is 0, which would call for a negative fuel), so the total fuel required is still just 2. + // > At first, a module of mass 1969 requires 654 fuel. Then, this fuel requires 216 more fuel (654 / 3 - 2). 216 then requires 70 more fuel, which requires 21 fuel, which requires 5 fuel, which requires no further fuel. So, the total fuel required for a module of mass 1969 is 654 + 216 + 70 + 21 + 5 = 966. + // > The fuel required by a module of mass 100756 and its fuel is: 33583 + 11192 + 3728 + 1240 + 411 + 135 + 43 + 12 + 2 = 50346. + assert_eq!(super::fuel_for_mass2(14), 2); + assert_eq!(super::fuel_for_mass2(1969), 966); + assert_eq!(super::fuel_for_mass2(100756), 50346); + } +}