82134657109111214130 64141325335143538472939597966 binary search lo binary search. given a key and...
TRANSCRIPT
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
Binary Search
lo
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
hi
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lo himid
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lo hi
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lo mid hi
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lo hi
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lo himid
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lohi
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lohimid
Binary Search
Binary search. Given a key and sorted array a[], find index isuch that a[i] = key, or report that no such index exists.
Invariant. Algorithm maintains a[lo] key a[hi].
Ex. Binary search for 33.
821 3 4 65 7 109 11 12 14130
641413 25 33 5143 53 8472 93 95 97966
lohimid