front	back	source	tags
What does binary search need from the array it searches?	A sorted array.	binary-search-lesson.md#the-invariant	concept
Why can binary search discard half of the range?	Every element in that half is on the wrong side of the middle one, because the array is sorted.	binary-search-lesson.md#the-invariant	concept
How is the middle index of the range lo to hi computed?	mid = (lo + hi) // 2, the floor of the middle.	binary-search-lesson.md#terms	detail
What is the largest number of probes for n elements?	⌊log2 n⌋ + 1	binary-search-lesson.md#counting-probes	detail
How many probes does a million elements take at most?	20	binary-search-lesson.md#counting-probes	detail
How does the worst case change when the array doubles?	It grows by one probe.	binary-search-lesson.md#counting-probes	concept
What does a lower-bound search return when no element qualifies?	The length of the array, an index that means none.	binary-search-sheet.md#type-t2-lower-bound	detail