Commit 47b39bf

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Use Hermann Bottenbruch's binary search (#9)

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Lines changed: 4 additions & 5 deletions

Original file line number	Diff line number	Diff line change
`@@ -79,16 +79,15 @@ pub fn part1(input: &[Reaction]) -> u64 {`
`79`	`79`	`/// Find the maximum amount of fuel possible from 1 trillion ore with an efficient binary search.`
`80`	`80`	`pub fn part2(input: &[Reaction]) -> u64 {`
`81`	`81`	`let threshold = 1_000_000_000_000;`
`82`		`- let mut start = 1;`
	`82`	`+ let mut start = 1_u64;`
`83`	`83`	`let mut end = threshold;`
`84`	`84`
`85`		`- while start < end {`
`86`		`- let middle = (start + end) / 2;`
	`85`	`+ while start != end {`
	`86`	`+ let middle = (start + end).div_ceil(2);`
`87`	`87`
`88`	`88`	`match ore(input, middle).cmp(&threshold) {`
`89`		`- Ordering::Less => start = middle + 1,`
`90`		`- Ordering::Equal => return middle,`
`91`	`89`	`Ordering::Greater => end = middle - 1,`
	`90`	`+ _ => start = middle,`
`92`	`91`	`}`
`93`	`92`	`}`
`94`	`93`

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