Java启动错误选择不包含主类型 [英] Java launch error selection does not contain a main type
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问题描述
import java.util.Arrays;
import java.util.Scanner;
public class SliceandDice {
void main（String args []）{
System.out.println（This is the BIGGEST program console）;
System.out.println（每个输入行将是由COMMA分隔的一对数字。）;
System.out.println（第一个数字必须是小于10000的无符号数字。最大例如：9999）;
System.out.println（第二个数字是'target'数字。
System.out.println（要输入的输入行的示例：）;
System.out.println（4721,75）; $ int $ i = 1; i <6; i ++）//每次在这个循环中，我们有一个新的
// set。
{
System.out.println（根据上面的语法规则键入一对数字）;
String iLine; //声明一个变量来保存名称。
扫描仪=新扫描仪（System.in）;
iLine = in.nextLine（）; //从控制台读取一行。
in.close（）; //注2
NumberSet set = ParseRawInput（i，iLine）;
if（set.IsValid（））{
System.out.println（有效输入。卡片号撕开：+ set.getCardNumber（）
+;目标号码： + set.getTargetNumber（））;
String cardNumber = set.getCardNumber（）;
int target = set.getTargetNumber（）;
AnalyzeNumber（cardNumber，target）; //解决这套
//数字
} else {
System.out.println（Invalid set of numbers。输入格式：nnnn，tttt）;
}
}
}
private void AnalyzeNumber（String cn，int t）{
int n = cn.length（）;
int m = n;
int sums = 4 + 3 + 2 + 1;
int [] possibleAnswers = new int [sums];
int answer = 0; （int digits = 1; digits
答案++;
}
System.out.println（-----------）;
possibleAnswers [answer] = PossibleAnswer（1，2，cn）;
答案++;
possibleAnswers [answer] = PossibleAnswer（1，3，cn）;
答案++;
System.out.println（-----------）;
possibleAnswers [answer] = PossibleAnswer（2，2，cn）;
答案++;
System.out.println（-----------）;
int finalAnswer = FindBiggestNearTarget（possibleAnswers，t）;
System.out.println（Best sum（closet to target）=+ String.valueOf（finalAnswer））;
}
private int PossibleAnswer（int extender，int lengthDigits，String cn）{
// extender =>哪个数字位置获得多长度调整
int n = cn.length（）;
int [] number = new int [n]; //持有个人加成
int sum = 0;
int LEN = 1; //我们需要的默认长度
String addends =;
int i;
if（extender == 0）{
i = 0;
while（i< n）{
addends + = cn.substring（i，lengthDigits）++;
number [i] = Integer.parseInt（cn.substring（i，lengthDigits））;
sum + = number [i];
i = i + lengthDigits; //总是递增至少1个位置
if（i + lengthDigits> n）
lengthDigits = 1;
}
System.out.println（addends +=+ String.valueOf（sum））;
返还金额
}
if（extender == 1）{
i = 0;
while（i< n）{
addends + = cn.substring（i，LEN）++;
number [i] = Integer.parseInt（cn.substring（i，LEN））;
sum + = number [i];
if（i == 0）{
i ++;
LEN = lengthDigits;
} else if（i == 1）{
i = i + lengthDigits; // i = 3（last number）
LEN = 1;
} else if（i == 2）{
i = 1;
LEN = 3;
} else {
i = n; //强制退出while循环
}
if（i + LEN> n）
LEN = 1;
}
System.out.println（addends +=+ String.valueOf（sum））;
返还金额
}
if（extender == 2）{
i = 0;
while（i< n）{
addends + = cn.substring（i，LEN）++;
number [i] = Integer.parseInt（cn.substring（i，LEN））;
sum + = number [i];
i = i + LEN; //总是递增至少1个位置
if（i == extender）{
LEN = lengthDigits;
}
if（i + LEN> n）
i = n; //强制退出
}
System.out.println（addends +=+ String.valueOf（sum））;
返还金额
}
return 0;
}
private int FindBiggestNearTarget（int [] possibles，int target）{
int [] sumArray = possibles;
Arrays.sort（sumArray）;
//用于交换值的临时变量
int temp;
//反转数组
for（int i = 0; i< sumArray.length / 2; ++ i）{
temp = sumArray [i];
sumArray [i] = sumArray [sumArray.length - i - 1];
sumArray [sumArray.length - i - 1] = temp;
}
for（int i = 0; i< sumArray.length; i ++）{
if（sumArray [i]< target）{
return sumArray [I];
}
}
return -1; //不应该发生
}
public static NumberSet ParseRawInput（int i，String rawInput）{
NumberSet errorSet = new NumberSet（-1，，0）;
// string [] stringArray = rawInput.Split（new char [] {'，'}）;
String [] stringArray = rawInput.toString（）。split（rawInput，'，'）;
if（stringArray.length！= 2）
return errorSet; //确保2个令牌由逗号分隔
//在第一个令牌上工作：
String cardNumberString = stringArray [0] .trim（）; //修剪任何空格
//从此令牌
if（cardNumberString.length（）> 4）
return errorSet; //确保令牌是4个字节或更少
//声明标记为整数
int cardNumber = Integer.parseInt（cardNumberString）;
//在第二个令牌上工作：
String targetNumberString = stringArray [1] .trim（）; //修剪
//空白从
// token
if（targetNumberString.length（）> 4）
return errorSet; //确保令牌是4字节以下
int targetNumber = Integer.parseInt（targetNumberString）; //转换成
// int
NumberSet validSet = new NumberSet（i，cardNumberString，targetNumber）;
return validSet;
}
}
class NumberSet {
// Java getter& setter
private String CardNumber;
private int TargetNumber;
private int SetNumber;
public int getSetNumber（）{
return this.SetNumber;
}
public String getCardNumber（）{
return this.CardNumber;
}
public int getTargetNumber（）{
return this.TargetNumber;
}
public NumberSet（int sn，String cn，int t）{
this.SetNumber = sn;
this.CardNumber = cn;
this.TargetNumber = t;
}
public Boolean IsValid（）{
if（this.SetNumber< 0）
return false;
返回true;
}
}
解决方案
你无法像C ++那样定义主要的方法。
对于Java解释器，主要方法必须始终为公共和静态。因此，您需要将主要方法签名更改为
public static void main（String args []）
尝试一下，随时问一下。 ： - ）
I am a total newbie in Java and Eclipse. I googled for lots of help but still confused. From Eclipse I click run then choose Java application and I get this error immediately. Here is my source code:
import java.util.Arrays;
import java.util.Scanner;
public class SliceandDice {
void main(String args[]) {
System.out.println("This is the BIGGEST program console");
System.out.println("Each input line will be a pair of numbers separated by a COMMA.");
System.out.println("First number must be an unsigned number less than 10000. Max example: 9999");
System.out.println("Second number is the 'target' number.");
System.out.println("Example of an input line to be typed:");
System.out.println(" 4721 , 75");
for (int i = 1; i < 6; i++) // each time in this loop, we have a new
// set.
{
System.out.println("Type a pair of numbers according to the syntax rules above:");
String iLine; // Declare a variable to hold the name.
Scanner in = new Scanner(System.in);
iLine = in.nextLine(); // Read one line from the console.
in.close(); // Note 2
NumberSet set = ParseRawInput(i, iLine);
if (set.IsValid()) {
System.out.println("Valid inputs. Card Number to tear apart:" + set.getCardNumber()
+ "; Target Number: " + set.getTargetNumber());
String cardNumber = set.getCardNumber();
int target = set.getTargetNumber();
AnalyzeNumber(cardNumber, target); // solve for this set of
// numbers
} else {
System.out.println("Invalid set of numbers. Enter in format: nnnn,tttt");
}
}
}
private void AnalyzeNumber(String cn, int t) {
int n = cn.length();
int m = n;
int sums = 4 + 3 + 2 + 1;
int[] possibleAnswers = new int[sums];
int answer = 0;
for (int digits = 1; digits < m; digits++) {
possibleAnswers[answer] = PossibleAnswer(0, digits, cn);
answer++;
}
System.out.println("-----------");
possibleAnswers[answer] = PossibleAnswer(1, 2, cn);
answer++;
possibleAnswers[answer] = PossibleAnswer(1, 3, cn);
answer++;
System.out.println("-----------");
possibleAnswers[answer] = PossibleAnswer(2, 2, cn);
answer++;
System.out.println("-----------");
int finalAnswer = FindBiggestNearTarget(possibleAnswers, t);
System.out.println("Best sum (closet to target) = " + String.valueOf(finalAnswer));
}
private int PossibleAnswer(int extender, int lengthDigits, String cn) {
// extender => which digit position gets multilength adjustment
int n = cn.length();
int[] number = new int[n]; // holds individual addends
int sum = 0;
int LEN = 1; // default length when we need it
String addends = "";
int i;
if (extender == 0) {
i = 0;
while (i < n) {
addends += cn.substring(i, lengthDigits) + " + ";
number[i] = Integer.parseInt(cn.substring(i, lengthDigits));
sum += number[i];
i = i + lengthDigits; // always increment at least 1 position
if (i + lengthDigits > n)
lengthDigits = 1;
}
System.out.println(addends + " = " + String.valueOf(sum));
return sum;
}
if (extender == 1) {
i = 0;
while (i < n) {
addends += cn.substring(i, LEN) + " + ";
number[i] = Integer.parseInt(cn.substring(i, LEN));
sum += number[i];
if (i == 0) {
i++;
LEN = lengthDigits;
} else if (i == 1) {
i = i + lengthDigits; // i = 3 (last number)
LEN = 1;
} else if (i == 2) {
i = 1;
LEN = 3;
} else {
i = n; // force exit of while loop
}
if (i + LEN > n)
LEN = 1;
}
System.out.println(addends + " = " + String.valueOf(sum));
return sum;
}
if (extender == 2) {
i = 0;
while (i < n) {
addends += cn.substring(i, LEN) + " + ";
number[i] = Integer.parseInt(cn.substring(i, LEN));
sum += number[i];
i = i + LEN; // always increment at least 1 position
if (i == extender) {
LEN = lengthDigits;
}
if (i + LEN > n)
i = n; // force out of loop
}
System.out.println(addends + " = " + String.valueOf(sum));
return sum;
}
return 0;
}
private int FindBiggestNearTarget(int[] possibles, int target) {
int[] sumArray = possibles;
Arrays.sort(sumArray);
// temporary variable for swapping values
int temp;
// reverse the array
for (int i = 0; i < sumArray.length / 2; ++i) {
temp = sumArray[i];
sumArray[i] = sumArray[sumArray.length - i - 1];
sumArray[sumArray.length - i - 1] = temp;
}
for (int i = 0; i < sumArray.length; i++) {
if (sumArray[i] < target) {
return sumArray[i];
}
}
return -1; // should not occur
}
public static NumberSet ParseRawInput(int i, String rawInput) {
NumberSet errorSet = new NumberSet(-1, "", 0);
// string[] stringArray = rawInput.Split( new char[] { ','});
String[] stringArray = rawInput.toString().split(rawInput, ',');
if (stringArray.length != 2)
return errorSet; // ensure 2 tokens separated by comma
// work on 1st token:
String cardNumberString = stringArray[0].trim(); // trim any whitespace
// from this token
if (cardNumberString.length() > 4)
return errorSet; // ensure token is 4 bytes or less
// declare token as integer
int cardNumber = Integer.parseInt(cardNumberString);
// work on 2nd token:
String targetNumberString = stringArray[1].trim(); // trim any
// whitespace from
// token
if (targetNumberString.length() > 4)
return errorSet; // ensure token is 4 bytes or less
int targetNumber = Integer.parseInt(targetNumberString); // convert into
// int
NumberSet validSet = new NumberSet(i, cardNumberString, targetNumber);
return validSet;
}
}
class NumberSet {
// Java getter & setter
private String CardNumber;
private int TargetNumber;
private int SetNumber;
public int getSetNumber() {
return this.SetNumber;
}
public String getCardNumber() {
return this.CardNumber;
}
public int getTargetNumber() {
return this.TargetNumber;
}
public NumberSet(int sn, String cn, int t) {
this.SetNumber = sn;
this.CardNumber = cn;
this.TargetNumber = t;
}
public Boolean IsValid() {
if (this.SetNumber < 0)
return false;
return true;
}
}
解决方案
You cannot define the main method as you do in C++.
For the Java interpreter, the main method must always be public and static. So you need to change your main method signature to
public static void main(String args[])
Try this, and feel free to ask further. :-)
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