一些简单的函数

  忽然发现在注重一些框架的同时,忘记了最基本的算法,就像人生在不停的追求切忘了本初自身生命的意义.

          终于决定写下来,希望也能对看到的人有帮助.

        对String的操作是java中无需提示的基本功,我想其他的语言也不类外,就像我们说话先学的你好.

       public class String1 {

                    /**

                       *

                       * 找出字符串中包含的数字

                          */

                 public static void StringNum(String str){

                             String regex = "[^0-9]";

                             String subNum = str.replaceAll(regex, "").trim();

                              System.out.print(subNum);

                }

               public static void main(String [] args){

                            String s ="ads123";

                            StringNum(s);

               }

  }

        

          递归和迭代

          public class Factorial {

/**

  * 用递归法写出阶乘的函数

  */

public static void main(String[] args) {

  int num = 5;

  Iterative(num);

System.out.println(Iterative(num));

}

public static int Iterative(int num) {

//递归

  if (num <= 0) {

   return 1;

  }

  return num * Iterative(num - 1);

  //迭代  

//  int result=num*(num-1);

//  for(int i = 1;i<num-1;i++){

//   result=result*(num-i-1);

//  

//  }

//  return result;

}

}

   对流程的控制

public class FindNum {

/**

  * 找出数组中重复次数最多的数字MaxNum和它重复的次数MaxCount

  */

public static void findNum(int num[]) {

  int MaxCount = Integer.MIN_VALUE, MaxNum = 0;

  int temp = 1;

  for (int i = 1; i <= num.length; i++) {

   int count = 1;

   for (int j = num.length - 1; j > i; j--) {

    while (num[i] == num[j]) {

     count++;

     break;

    }

    if (count > temp) {

     temp = count;

     MaxNum = num[i];

     MaxCount = temp;

    }

   }

  }

  System.out.print("MaxNum=" + MaxNum + "," + "MaxCount=" + MaxCount);

}

public static void main(String[] args) {

  int num[] = { 3, 4, 2, 3, 456, 7, 5, 2, 6, 2, 0, 2, 9 };

  findNum(num);

}

}

以上是我自己写的,肯定不是最好的,这是我现阶段能写出的.希望将来能写出优雅的语句.