1、搜索都是建立在排好序的序列之上再搜索。
（1）二分法搜索
拿中間的數和要搜索的數比較。
（2）排序的順序要求是升序。

package com.winney.countThree;

public class TestSearch {

    public static void main(String[] args) {
        // TODO 自動生成的方法存根
        int[] in1 = {1,0,9,2,3,5,8,4,6,7,44,33};
        int[] in2 = {1,0,9,26,7,44,33};

        in1 = selectionSorted(in1);
        printArray(in1);
        in2 = bubbleSorted(in2);
        printArray(in2);
        System.out.println(binarySorted(44,in1));
        System.out.println(binarySorted(7,in2));
    }
    
    public static int[] selectionSorted(int[] in) {
        int k,temp;
        for(int i=0; i<in.length; i++) {
            k = i;
            for(int j=i+1; j<in.length; j++) {
                if (in[k] > in[j]) {
                    k =j;
                }
            }
            if ( k != i) {
                temp = in[i];
                in[i] = in[k];
                in[k] = temp;
            }
        }
        return in;
    }
    
    public static int[] bubbleSorted(int[] in) {
        int temp;
        int  len = in.length;
        for(int i=len-1; i>=1; i--) {
            for(int j=0; j<=i-1; j++) {
                if( in[j] > in[j+1] ) {
                    temp = in[j];
                    in[j] = in[j+1];
                    in[j+1] = temp;
                }
            }
        }
        return in;
    }
    
    public static int binarySorted(int aim, int[] in) {
        int start = 0;
        int end = in.length-1;
        int m = end / 2;
        
        while(start <= end) {
            if ( aim == in[m] ) {
                return m;
            }
            if( aim > in[m] ) {
                start = m+1;
                m = (start + end)/2;
            }
            if( aim < in[m] ) {
                end = m-1;
                m = (start + end)/2;
            }
        }
        return -1;
    }
    
    public static void printArray(int[] in) {
        for(int i=0; i<in.length; i++) {
            System.out.print(" " + in[i]);
        }
        System.out.println();
    }
}

2、日期對象的排序以及二分法搜索

class Date {
    private String today;
    int year,month,day;
    Date(int year, int month, int day) {
        this.year= year;
        this.month = month;
        this.day = day;
        today= year+"-"+month+"-"+day;
        //System.out.println("轉換為日期是");
    }
    
    public String getToday() {
        return today;
    }
    
    public int compare(Date d) {
        return year > d.year ? 1
                : year < d.year ? -1
                :month > d.month ? 1
                : month < d.month ? -1
                :day > d.day ? 1
                :day < d.day? -1 : 0;
    }
    
    public static void printDates(Date[] dates) {
        for( int i=0; i<dates.length; i++) {
            System.out.print(dates[i].today+"  ");
        }
        System.out.println();
    }
    
    public static Date[] dateSorted(Date[] dates) {
        int k;
        Date temp;
        int len = dates.length;
        for ( int i=0; i<len; i++) {
            k = i;
            for (int j=i+1; j<len; j++) {
                if (dates[k].compare(dates[j]) == 1 ) {
                    k = j;
                }
            }
            if (k != i) {
                temp = dates[i];
                dates[i] = dates[k];
                dates[k] = temp;
            }
        }
        return dates;
    }
    
    public static int binarySearchDate(Date[] dates, Date d) {
        int start = 0;
        int end = dates.length -1;
        int m;
        while (start <= end) {
            m = (start + end) / 2;
            if (d.compare(dates[m]) == 0) {
                return m;
            }
            else if (d.compare(dates[m]) == 1) {
                start = m+1;
            }
            else if (d.compare(dates[m]) == -1) {
                end = m-1;
            }
            m = start + end;
        }
        return -1;
    }
}

public class TestArrayDate {

    public static void main(String[] args) {
        // TODO 自動生成的方法存根
        Date[] dates;
        dates = new Date[6];
        int j=100;
        for(int i=0; i<6; i++) {
            dates[i] = new Date(1+i,2+i,3+i);
            if( i%2 == 0) {
                dates[i] = new Date(j+i,j+2,j);
            }
        }
        Date d = new Date(100,102,100);
        Date.printDates(dates);
        Date.dateSorted(dates);
        Date.printDates(dates);
        int result = Date.binarySearchDate(dates,d);
        System.out.print(result);
    }

}