2015: day04: optimize string allocations

This commit is contained in:
Antoine Martin 2019-12-03 15:22:25 +01:00
parent ce83c56841
commit 33b89f6269

View file

@ -13,15 +13,17 @@ pub fn run() -> Result<()> {
fn part1(input: &str) -> Result<u64> {
let input = input.trim_end();
let mut content = String::from(input);
let mut hasher = Md5::new();
for i in 0.. {
let content = format!("{}{}", input, i);
content.truncate(input.len());
content.extend(i.to_string().chars());
hasher.input(content);
let res = format!("{:x}", hasher.result_reset());
if &res[..5] == "00000" {
hasher.input(&content);
let res = hasher.result_reset();
if &res[..2] == &[0, 0] && res[2] <= 0x0f {
return Ok(i);
}
}