51 lines
1.0 KiB
Rust
51 lines
1.0 KiB
Rust
const LOOP_COUNT: i32 = 1_000_000;
|
|
const EXPECTED_CHECKSUM: i32 = 3_875_011;
|
|
|
|
struct ArrayRecord {
|
|
digits: [i32; 8],
|
|
}
|
|
|
|
fn configured_loop_count() -> i32 {
|
|
let mut input = String::new();
|
|
if std::io::stdin().read_line(&mut input).is_err() {
|
|
return LOOP_COUNT;
|
|
}
|
|
|
|
input
|
|
.trim()
|
|
.parse::<i32>()
|
|
.ok()
|
|
.filter(|value| *value > 0)
|
|
.unwrap_or(LOOP_COUNT)
|
|
}
|
|
|
|
fn make_record() -> ArrayRecord {
|
|
ArrayRecord {
|
|
digits: [3, 1, 4, 1, 5, 9, 2, 6],
|
|
}
|
|
}
|
|
|
|
fn array_struct_field_loop(limit: i32) -> i32 {
|
|
let record = make_record();
|
|
let mut i = 0;
|
|
let mut acc = 11;
|
|
|
|
while i < limit {
|
|
acc += record.digits[(i % 8) as usize];
|
|
acc = if acc > 1_000_000_000 {
|
|
acc - 1_000_000_000
|
|
} else {
|
|
acc
|
|
};
|
|
i += 1;
|
|
}
|
|
|
|
acc
|
|
}
|
|
|
|
fn main() {
|
|
let result = array_struct_field_loop(configured_loop_count());
|
|
println!("{}", result);
|
|
std::process::exit(if result == EXPECTED_CHECKSUM { 0 } else { 1 });
|
|
}
|