edu.princeton.cs.algs4

Class BinarySearch

java.lang.Object

edu.princeton.cs.algs4.BinarySearch

public class BinarySearch
extends java.lang.Object

The BinarySearch class provides a static method for binary searching for an integer in a sorted array of integers.

The indexOf operations takes logarithmic time in the worst case.

For additional documentation, see Section 1.1 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.

Method Summary

Modifier and Type	Method and Description
static int	indexOf(int[] a, int key) Returns the index of the specified key in the specified array.
static void	main(java.lang.String[] args) Reads in a sequence of integers from the whitelist file, specified as a command-line argument; reads in integers from standard input; prints to standard output those integers that do not appear in the file.
static int	rank(int key, int[] a) Deprecated. Replaced by indexOf(int[], int).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

indexOf

public static int indexOf(int[] a,
                          int key)

Returns the index of the specified key in the specified array.

Parameters:

a - the array of integers, must be sorted in ascending order

key - the search key

Returns:

index of key in array a if present; -1 otherwise

rank

@Deprecated
public static int rank(int key,
                                   int[] a)

Deprecated. Replaced by indexOf(int[], int).

Returns the index of the specified key in the specified array. This function is poorly named because it does not give the rank if the array has duplicate keys or if the key is not in the array.

Parameters:

key - the search key

a - the array of integers, must be sorted in ascending order

Returns:

index of key in array a if present; -1 otherwise

main

public static void main(java.lang.String[] args)

Reads in a sequence of integers from the whitelist file, specified as a command-line argument; reads in integers from standard input; prints to standard output those integers that do not appear in the file.

Parameters:

args - the command-line arguments