diff --git a/src/slice/quicksort.rs b/src/slice/quicksort.rs index 87fb724c3..fd8ab0f2d 100644 --- a/src/slice/quicksort.rs +++ b/src/slice/quicksort.rs @@ -191,25 +191,25 @@ where // This binary heap respects the invariant `parent >= child`. let sift_down = |v: &mut [T], mut node| { loop { - // Children of `node`: - let left = 2 * node + 1; - let right = 2 * node + 2; + // Children of `node`. + let mut child = 2 * node + 1; + if child >= v.len() { + break; + } // Choose the greater child. - let greater = if right < v.len() && is_less(&v[left], &v[right]) { - right - } else { - left - }; + if child + 1 < v.len() && is_less(&v[child], &v[child + 1]) { + child += 1; + } // Stop if the invariant holds at `node`. - if greater >= v.len() || !is_less(&v[node], &v[greater]) { + if !is_less(&v[node], &v[child]) { break; } // Swap `node` with the greater child, move one step down, and continue sifting. - v.swap(node, greater); - node = greater; + v.swap(node, child); + node = child; } };