最大值、最小值、平均值、和、數組反轉、數組排序

標籤：最大值、最小值、平均值、和、數組反轉、數組排序

import java.util.Arrays;import java.util.Scanner;public class ArrayUtils {    //擷取數組的最大值    public static void main(String[] args) {//        int[] arr=new int[]{12,4,76,-9,0,44,-87,66};        int num;        Scanner s;                while(true){           try{               System.out.println("請輸入數組元素個數：");               s=new Scanner(System.in);                          num=s.nextInt();               break;           }catch(Exception e)           {               System.out.println("輸入錯誤，請重新輸入！！");           }        }                        int[] arr=new int[num];         System.out.println("請輸入"+num+"個數組元素");        for(int i=0;i<num;i++){            arr[i]=s.nextInt();        }        s.close();        Array a1=new Array();        Array.getMaxValue(arr);//最大值        a1.getMinValue(arr);//最小值        a1.getAvg(arr);//平均值        a1.getSum(arr);//求和        System.out.print("數組反轉方法一：");        System.out.println();        a1.fanZhuan(arr);//數組反轉        System.out.println();        System.out.print("數組反轉方法二：");        System.out.println();        a1.fanZhuanShuZu(arr);                System.out.println();        System.out.print("快速排序：");        System.out.println();        a1.sort(arr);//數組升序排序        System.out.println();        System.out.print("冒泡排序--升序：");        System.out.println();        a1.maoPao(arr);//冒泡排序        System.out.println();        System.out.print("排序方法二--升序：");        System.out.println();        a1.paiXu(arr);        System.out.println();        System.out.print("排序方法三--降序：");        System.out.println();        a1.paiSort(arr);    }}class Array{    //擷取最大值    public static void getMaxValue(int[] arr){        int maxValue = arr[0];        for(int i = 1;i < arr.length;i++){            if(maxValue < arr[i]){                maxValue = arr[i];            }        }        System.out.println("最大值為：" + maxValue);            }    //擷取最小值    public void getMinValue(int[] arr){        int minValue = arr[0];        for(int i = 1;i < arr.length;i++){            if(minValue > arr[i]){                minValue = arr[i];            }        }        System.out.println("最小值為：" + minValue);    }    //擷取平均值    public void getAvg(int[] arr){        double avg = 0.0;//        int sum1 = 0;//        for(int i = 0;i < arr.length;i++){//            sum1 += arr[i];//        }//        avg = (double)sum1 / arr.length;        avg =(double) getSum(arr) / arr.length;        System.out.println("平均值為：" + avg);    }    //求和運算    public int  getSum(int[] arr){        int sum = 0;        for(int i = 0;i < arr.length;i++){            sum += arr[i];        }        System.out.println("總和為:" + sum);        return sum;    }    //數組元素的反轉方法一    public void fanZhuan(int[] arr){        for(int x=0,y=arr.length-1;x<y;x++,y--){            int temp=arr[x];            arr[x]=arr[y];            arr[y]=temp;        }        System.out.print("{");        for(int i = 0;i < arr.length;i++){            if(i == arr.length - 1){                System.out.print(arr[i] + "}");                break;            }            System.out.print(arr[i] + ",");        }    }        //數組反轉方法二    public void fanZhuanShuZu(int[] arr){        for(int i=0;i<arr.length/2;i++){            int temp=arr[i];            arr[i]=arr[arr.length-1-i];            arr[arr.length-1-i]=temp;        }        System.out.print("{");        for(int i = 0;i < arr.length;i++){            if(i == arr.length - 1){                System.out.print(arr[i] + "}");                break;            }            System.out.print(arr[i] + ",");        }    }    //數組生序排列    public void sort(int[] arr){        Arrays.sort(arr);        System.out.print("{");        for(int i = 0;i < arr.length;i++){            if(i == arr.length - 1){                System.out.print(arr[i] + "}");                break;            }            System.out.print(arr[i] + ",");        }    }    //冒泡排序    public void maoPao(int[] arr){        for(int i=0;i<arr.length;i++){            for(int j=i;j<arr.length;j++){                if(arr[i]>arr[j]){                    int temp=arr[i];                    arr[i]=arr[j];                    arr[j]=temp;                                    }            }        }        System.out.print("{");        for(int i = 0;i < arr.length;i++){            if(i == arr.length - 1){                System.out.print(arr[i] + "}");                break;            }            System.out.print(arr[i] + ",");        }    }    //排序方法二    public void paiXu(int[] arr){        for(int i = 0;i <arr.length - 1 ;i++){            for(int j = 0;j < arr.length - 1 - i;j++){                if(arr[j] > arr[j + 1]){                    int temp = arr[j];                    arr[j] = arr[j + 1];                    arr[j + 1] = temp;                }            }                    }        System.out.print("{");        for(int i = 0;i < arr.length;i++){            if(i == arr.length - 1){                System.out.print(arr[i] + "}");                break;            }            System.out.print(arr[i] + ",");        }    }    //排序方法三    public void paiSort(int[] arr){        for(int i=0;i<arr.length;i++){            for(int j=0;j<arr.length;j++){                if(arr[i]>arr[j]){                    int temp=arr[i];                    arr[i]=arr[j];                    arr[j]=temp;                                    }            }        }        System.out.print("{");        for(int i = 0;i < arr.length;i++){            if(i == arr.length - 1){                System.out.print(arr[i] + "}");                break;            }            System.out.print(arr[i] + ",");        }    }}

本文出自 “第一天的課” 部落格，請務必保留此出處http://5453607.blog.51cto.com/5443607/1532530