A simple example of Selection Sort, Linear Search, and Binary Search. --- Originally for my Programming Fundamentals for CIS Majors 2 class at the University of Florida. The discussion instructions can be found here: http://www.cise.ufl.edu/class/cop3503fa12/discussion/disc11/ (as long as link stays live!)

searchingAndSorting.java

import java.lang.Math;
import java.util.Arrays;

/**
 * Discussion 11 COP 3503 Fall 2012
 *
 */
 
public class SearchingAndSorting {

  public static void main(String[] args) {
		double[] values = {6.4, 194.5, 4.3, 4.6, 65.3, 34.666, 1.44, 0.98, 0.11, 23.2, 5.5, 100.1};
		
		selectionSort(values);
		
		System.out.print("Sorted Array of length " + values.length + " :");
		for (double i : values)
			System.out.print(" " + i);
		
		// now search
		double toSearch = 3.4;
		int index = linearSearch(values, toSearch);
		System.out.println("\n\nClosest value with linear search for " + toSearch +  ": " + values[index]);
		
		// Arrays.sort(values);
		
		toSearch = 23.2;
		index = binarySearch(values, toSearch);
		System.out.println("\n\nClosest value with binary search for " + toSearch +  ": " + values[index]);
	}

	// Swaps two values at indices i and j in an array
	public static void swap(double[] a, int i, int j) {
		double first = a[i];
		a[i] = a[j];
		a[j] = first;
   	 }
	
	// Returns the index of the minimum value
        // Finds minimum values between indices start and end
	public static int minimum(double[] a, int start, int end) {
		int min = start;
		for(int i = start + 1; i <= end; i++){
			if(a[i] < a[min]){
				i = min;
			}
		}
		return min;	
   	 }
	
	// Selection sort of the double array - uses the swap and min methods
	public static void selectionSort(double[] a) {
		for(int i = 0; i < a.length - 1; i++){
			int minIndex = i;
			for(int j = i + 1; j < a.length; j++){
				if(a[j] < a[minIndex]){
					minIndex = j;
				}
			}
			
			if(minIndex != i){
				swap(a, i, minIndex);
			}
		}
  	  }
	
	// Linear Search
        // returns the index of the value closest to "toSearch"
	public static int linearSearch(double[] values, double toSearch) {
		int indexMatched = 0;
		double difference = Math.abs(values[0] - toSearch);
		for(int i = 1; i < values.length; i++){
			if(Math.abs(values[i] - toSearch) <= difference){
				indexMatched = i;
				difference = Math.abs(values[i] - toSearch);
			}
		}
        
		return indexMatched;
   	 }
	
	// Binary Search
        // returns the index of the value closest to "toSearch"
	public static int binarySearch(double[] values, double toSearch) {
		int indexMatched = 0;
		int left = 0;
		int right = values.length;
		double difference = Math.abs(values[0] - toSearch);
		while(left <= right){
			int i = (left + right) / 2;
			if(Math.abs(values[i] - toSearch) <= difference){
				indexMatched = i;
				difference = Math.abs(values[i] - toSearch);
			}
			if(toSearch < values[i]){
				right = i - 1;
			}
			
			else if(toSearch > values[i]){
				left = i + 1;
			}
			
			else{
				indexMatched = i;
				break;
			}
		}
		
		return indexMatched;
	}
}