第二次作业（个人项目实践）

1. 设计一个类（不妨叫做A ），实现对一维数组(a[100])的指定范围内的元素相加运算。

package aaa;
import java.util.Scanner;//用于java输入语句的包。

public class A {
public static void main(String[]args)
{
int[] arr={-2574,-4010,8243,771,2447,-5197,2556,8044,3314,3617,6065,-2817,3131,6318,2186,-113,629,-2582,-37,-1520,164,2055,-5936,5912,1717,5988,4781,5757,892,-4394,8034,2213,-1080,-2080,5364,106,2657,566,3940,-5116,4583,1806,6555,2621,-7197,528,1626,18,1049,6243,3198,4397,-1325,9087,936,-6291,662,-178,135,-3473,-2385,-165,1713,-7949,-4234,1138,2212,104,6968,-3632,3801,1137,-1296,-1215,4272,6223,-5922,-7723,7044,-2938,-8180,1356,1159,-4022,-3713,1158,-8715,-4081,-2541,-2555,-2284,461,940,6604,-3631,3802,-2037,-4354,-1213,767};
int sum=0;
Scanner sc = new Scanner(System.in) ;//定义Scanner类的对象sc,接收来自键盘的数据
System.out.println("x轴开始:");
int start=sc.nextInt();
System.out.println("x轴结束:");
int end=sc.nextInt();
System.out.println("str为：" +start);
System.out.println("end为：" +end);
System.out.println("第"+start+"个元素到第"+end+"个元素相加和为");
for(int i=start;i<=end;i++)
sum+=arr[i];
System.out.println(sum);
}
}

运行结果：

2. 设计一个类（不妨叫做B ），实现对二维数组(a
[M])的指定范围内的元素相加运算。

package aaa;
import java.util.Scanner;

public class B
{
public static void main(String[]args)
{
int[][]
　　a={
　　　　{-2574,-4010,8243,771,2447,-5197,2556,8044,3314,3617,6065,-2817,3131,6318,2186,-113,629,-2582,-37,-1520,164,2055,-5936,5912,1717,5988,4781,5757,892,-4394,8034,2213,-1080,-2080,5364,106,2657,566,3940,-5116,4583,1806,6555,2621,-7197,528,1626,18,1049,6243,3198,4397,-1325,9087,936,-6291,662,-178,135,-3473,-2385,-165,1713,-7949,-4234,1138,2212,104,6968,-3632,3801,1137,-1296,-1215,4272,6223,-5922,-7723,7044,-2938,-8180,1356,1159,-4022,-3713,1158,-8715,-4081,-2541,-2555,-2284,461,940,6604,-3631,3802,-2037,-4354,-1213,767},
　　　　{2740,-4182,-5632,-2966,-1953,567,-8570,1046,2211,1572,-2503,-1899,3183,-6187,3330,3492,-464,-2104,316,8136,470,50,466,-1424,5809,2131,6418,-3018,6002,-8379,1433,1144,2124,1624,-602,-5518,5872,870,-5175,-3961,-427,-6284,2850,481,6175,141,-766,-1897,-748,-4248,366,4823,3003,1778,3256,2182,2253,5076,5540,-2650,2451,-1875,5482,-6881,-329,-969,-8032,-2093,612,1524,-5492,5758,-7401,-5039,3241,6338,3581,4321,-1072,4942,2131,210,-7045,-7514,7450,-1142,-2666,-4485,-639,2121,-5298,-3805,-1686,-2520,-1680,2321,-4617,-1961,2076,7309
}
}
　　int sum=0;
　　Scanner sc = new Scanner(System.in); //定义Scanner类的对象sc,接收来自键盘的数据
　　System.out.println("x轴开始:"); //将二维数组看作是平面直角坐标系，有x，y两个坐标
　　int startX = sc.nextInt();
　　System.out.println("x轴结束:");//1-2
　　int endX =sc.nextInt();
　　System.out.println("y轴开始:");//1-100
　　int startY = sc.nextInt();
　　System.out.println("y轴结束:");
　　int endY =sc.nextInt();
　　System.out.println("指定的范围是");
　　System.out.println("从("+startX+","+startY+")到"+"("+endX+","+endY+")的和为");
　　for(int i=startX-1;i<=endX-1;i++)
　　{
　　 for(int j=startY-1;j<=endY-1;j++)
　　　　{
　　　　 sum+=a[i][j];
　　　　 }
　　}
　　System.out.println(sum);
　}
}

运行结果：



3. 设计一个类（不妨叫做C ），实现对三维数组(a
[M][K])的指定范围内的元素相加运算。

package aaa;
import java.util.Scanner;

public class C {
public static void main(String[]args)
{
int sum=0;
int[][][] a = new int[][][]
{
{{-2574,-4010,8243,771,2447,-5197,2556,8044,3314,3617,6065,-2817,3131,6318,2186,-113,629,-2582,-37,-1520,164,2055,-5936,5912,1717,5988,4781,5757,892,-4394,8034,2213,-1080,-2080,5364,106,2657,566,3940,-5116,4583,1806,6555,2621,-7197,528,1626,18,1049,6243,3198,4397,-1325,9087,936,-6291,662,-178,135,-3473,-2385,-165,1713,-7949,-4234,1138,2212,104,6968,-3632,3801,1137,-1296,-1215,4272,6223,-5922,-7723,7044,-2938,-8180,1356,1159,-4022,-3713,1158,-8715,-4081,-2541,-2555,-2284,461,940,6604,-3631,3802,-2037,-4354,-1213,767}},
{{2740,-4182,-5632,-2966,-1953,567,-8570,1046,2211,1572,-2503,-1899,3183,-6187,3330,3492,-464,-2104,316,8136,470,50,466,-1424,5809,2131,6418,-3018,6002,-8379,1433,1144,2124,1624,-602,-5518,5872,870,-5175,-3961,-427,-6284,2850,481,6175,141,-766,-1897,-748,-4248,366,4823,3003,1778,3256,2182,2253,5076,5540,-2650,2451,-1875,5482,-6881,-329,-969,-8032,-2093,612,1524,-5492,5758,-7401,-5039,3241,6338,3581,4321,-1072,4942,2131,210,-7045,-7514,7450,-1142,-2666,-4485,-639,2121,-5298,-3805,-1686,-2520,-1680,2321,-4617,-1961,2076,7309}},
{{302,-7944,-6551,6648,-884,-6332,1188,-248,3902,-2171,-3782,-3510,6203,-636,-4605,4497,3187,-6278,1198,-7963,7647,-3022,-8267,7995,-1998,-4171,730,-8117,-1706,7601,-2454,-6161,-1810,243,-2841,-5377,2985,2328,177,5622,3596,3057,2830,-1151,6566,2254,6972,-3060,4063,367,84,3156,3880,-1530,5272,1385,-565,-1736,1267,-3863,-229,2072,2423,-7449,9555,2844,-1278,-3613,-919,4153,-4232,4032,-5732,199,4792,2498,-3344,-4193,2650,-579,3416,-3575,1822,-6936,-2661,-1873,414,2314,6844,7613,-7844,6680,5974,2208,-3597,6302,4396,-141,-1864,1939}}
};
Scanner sc = new Scanner(System.in) ; //定义Scanner类的对象sc,接收来自键盘的数据
System.out.println("x轴开始:");//将三维数组看作是空间直角坐标系，有x，y，z三个坐标
　　　　　int startX = sc.nextInt() ;
System.out.println("x轴结束:");x取值0-2
int endX =sc.nextInt();
System.out.println("y轴开始:");
int startY = sc.nextInt() ;
System.out.println("y轴结束:");
int endY =sc.nextInt();
System.out.println("z轴开始:");
int startZ = sc.nextInt() ;
System.out.println("z轴结束:");
int endZ =sc.nextInt();

for(int i=startX;i<=endX;i++)
{
for(int j=startY;j<=endY;j++)
{
for(int q=startZ;q<=endZ;q++)
{
sum+=a[i][j][q];
}
}
}
System.out.println("从("+startX+","+startY+","+startZ+")到"+"("+endX+","+endY+","+endZ+")的和为");
System.out.println(sum);
}
}

运行结果：



说实话，看到这个作业的时候真的是毫无头绪，就我所理解的，是要我们编写一个程序将老师给的excel里的数据导入到myeclipse中，并且将数据放到数组中，运用类来实现对一维数组、二维数据以及三维数组的元素相加运算，可是如何将excel中的那些数据导到myeclipse中就已经难倒了我。后来，我看了张振渊同学和林杰的博客，发现他们是通过手动导入的方式将数据导入，于是我看了他们的方法：
http://jingyan.baidu.com/article/c85b7a642ceff6003bac95f0.html， http://jingyan.baidu.com/article/a24b33cd5730bc19fe002b3e.html
分别导出一维数组、二维数组以及三维数组要用的数据。

虽然导出了数据，但是新的问题又出现了，要实现的是指定范围内的元素相加运算，那肯定要手动输入需要的范围，通过翻阅以前的Java书，我发现Scanner类可以实现从键盘读取数据，书上列出了Scanner类的常用方法，如Scanner（String source）可以构造一个新的Scanner（从指定字符串扫描数据）、int nextInt()（扫描读取下一个数据，该数据被标识为int值）等等。教材中列举了一个关于计算总金额的例子，

import java.until.Scanner;

public class TotalMon

{

7　　 public static void main(String[] args)

　　double totalMon,UnitPrice;

　　int num;

　　Scanner sc=new Scanner(System.in);

15　　 String str=sc.nextLine();

　　Scanner scan=new Scanner(str);

　　scan.useDelimiter(“/”);

21　　 UnitPrice=scan.nextDouble();

　　num=scan.nextInt();

　　totalMon=UnitPrice*num;

27　　 System.out.println(“总金额为:”+totalMon);

29  }

后来就尝试自己编写这次的代码，我是把测试数据放在代码中，比较繁琐，也有尝试用工具类和测试类才编写，但是还没有成功。我仔细看了其他人写的代码以及老师给的评论，都是把测试数据放在代码中，老师也一再强调代码优化问题，最好能从csv中读取excel的数据。通过这次实验，我收获很多，明白了编程要多钻研、多尝试，同时代码规范也很重要，这次写随笔我有注意自己文章的规范性。