几道编程题

直接上代码

试题1：

public class Test1 {

    static void convert(String str) {
        int count = 1; // 用于记录当前连续字符的数量
        char[] input = str.toCharArray();
        char pre = '\u0000', cur; // char为空判断
        char output;

        for (char ele : input) {
            cur = ele;
            if (cur == pre) {
                count++;
                // 连续两个字符
                if (count == 2) {

                    output = (char) traverse(cur,cur + 2);
                    System.out.print(output);
                }
                // 连续三个及以上字符
                if (count >= 3) {
                    output = (char) traverse(cur,cur + count - 2);
                    System.out.print(output);
                }
            } else {
                count = 1;
                pre = cur; // 赋值

                output = (char) traverse(cur,ele + 1);//traverse
                System.out.print(output);
            }

        }
        System.out.println();
    }

    static int traverse(char ch,int num)
    {
        boolean upper = false;
        if(Character.isUpperCase(ch))
        {
            upper = true;
        }
        // 越界z
        if(upper==false&&num>122)
        {
            num = (num-97)%26+97;//num = (char)(num-26);
            //System.out.println(num);
        }
        // 越界Z
        if(upper&&num >90)
        {
            num = (num-65)%26+65;//num = (char)(num-26);
        }
        return num;
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String input1 = "abcd";
        String input2 = "abbcd";// "abb";
        String input3 = "abbbcd";
        String input4 = "abbbbbcccd";
        String input5 = "abzzcdeeeg";

        convert(input1);
        convert(input2);
        convert(input3);
        convert(input4);
        convert(input5);

        System.out.println((char)67);
        System.out.println('a' > 96);
    }
}

试题2：

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

public class Test2 {

    static void sort(String str) {
        char[] input = str.toCharArray();

        /* 字符串替换思路
         * char[] replace = new char[input.length];
        for (int i = 0; i < input.length; i++) {
            // 这里可以用正则进行通配符的匹配
            if (input[i] == ',' || (input[i] > '1' && input[i] < '9')) {
                replace[i] = ' '; //数据替换
            } else
                replace[i] = input[i];
            //System.out.print(replace[i]);
        }
        String rep = String.valueOf(replace); //数据处理后的字符串
        System.out.println(rep);
        String[] array = rep.split(" "); //这里没有对string合法做验证

        HashMap<String, Integer> map = new HashMap<String, Integer>();
        for (String s : array) {
            if (s != "" && !s.equals("")) {
                map.put(s, s.length());
            }
        }*/

        HashMap<String, Integer> map = new HashMap<String, Integer>();
        StringBuffer temp = new StringBuffer();
        for(int i=0;i<input.length;i++)
        {
            // 小写大写字母
            if((input[i]>96&&input[i]<123)||(input[i]>64&&input[i]<91))
            {
                temp.append(input[i]);
            }
            // 即单词已经找到
            else if(temp.length()>1)
            {
                map.put(temp.toString(), temp.length());
                temp = new StringBuffer();// 置空处理
            }
        }

        List<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>(
                map.entrySet());

        //根据字符串长度进行排序
        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
            public int compare(Map.Entry<String, Integer> o1,
                    Map.Entry<String, Integer> o2) {
                return (o2.getValue() - o1.getValue());
                //return (o1.getKey()).toString().compareTo(o2.getKey());
            }
        });

        for (int i = 0; i < list.size(); i++) {
            String id = list.get(i).toString();
            System.out.print(id + " ");
        }
        System.out.println();

        for (Entry<String, Integer> e : list) {
            if (e.getValue() != 1)
                System.out.print(e.getKey() + " ");
        }

    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        String str1 = "some drivers drink when the d234drives";
        sort(str1);
    }
}

试题3：

public class Test3 {
 // 适合int范围内数
    static String minus(String s1, String s2) {
        char[] str1 = s1.toCharArray();
        char[] str2 = s2.toCharArray();

        int forward_number1 = 0, forward_number2 = 0; // 两个数的整数部分
        int backward_number1 = 0, backward_number2 = 0; // 两个数的小数部分对应的整数

        int len1 = str1.length, len2 = str2.length;
        int pos1 = -1, pos2 = -1;

        double number1, number2;

        if (s1.indexOf('.') != -1) {
            pos1 = s1.indexOf('.');
            pos2 = s2.indexOf('.');
        }

        for (int i = 0; i < str1.length; i++) {
            if (pos1 != -1 && i < pos1) {
                forward_number1 = forward_number1 * 10 + (str1[i] - '0');
            } else if (i > pos1)
                backward_number1 = backward_number1 * 10 + (str1[i] - '0');
        }
        // System.out.println(forward_number1 + " " + backward_number1);

        for (int i = 0; i < str2.length; i++) {
            if (pos2 != -1 && i < pos2) {
                forward_number2 = forward_number2 * 10 + (str2[i] - '0');
            } else if (i > pos2) {
                backward_number2 = backward_number2 * 10 + (str2[i] - '0');
            }
        }
        // System.out.println(forward_number2 + " " + backward_number2);

        // 更简单的处理方法是：直接将小数转换为整数
        int mul = (len1 - pos1) > (len2 - pos2) ? (len1 - pos1 - 1) : (len2
                - pos2 - 1);

        number1 = forward_number1 * Math.pow(10, mul) + backward_number1;
        number2 = forward_number2 * Math.pow(10, mul) + backward_number2;
        // System.out.println(number1 + " " + number2);

        double result = (number1 - number2) / Math.pow(10, mul);
        // System.out.println(result);

        return String.valueOf(result);
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        String s11 = "1.1";
        String s12 = "2.2";

        String s21 = "2.2";
        String s22 = "1.1";

        String s31 = "10.1";
        String s32 = "9.23";

        System.out.println(minus(s12, s11));
        System.out.println(minus(s22, s21));
        System.out.println(minus(s32, s31));
    }

}