英文:
Find the MIN/MAX/SUM from a Text File
问题
package net.codejava;
import java.io.FileReader;
import java.util.Scanner;
import java.io.FileNotFoundException;
import java.util.Arrays;
public class MyFile {
public static int[] toIntArray(String input, String delimiter) {
return Arrays.stream(input.split(delimiter)).mapToInt(Integer::parseInt).toArray();
}
public static void main(String[] args) throws FileNotFoundException {
int min = Integer.MAX_VALUE;
int max = Integer.MIN_VALUE;
double avg = 0.0;
int sum = 0;
int count = 0;
String[] numArray = new String[30];
int[] maxArray;
int[] minArray;
int[] sumArray;
try {
String myFile = "input.txt";
Scanner input = new Scanner(new FileReader(myFile));
while (input.hasNext()) {
input.next();
numArray[count] = input.next();
count++;
}
} catch (FileNotFoundException e) {
System.out.println("File not found!");
}
minArray = toIntArray(numArray[0], ",");
maxArray = toIntArray(numArray[1], ",");
sumArray = toIntArray(numArray[2], ",");
System.out.println("The min of " + Arrays.toString(minArray) + " is " + Arrays.stream(minArray).min().getAsInt());
System.out.println("The max of " + Arrays.toString(maxArray) + " is " + Arrays.stream(maxArray).max().getAsInt());
System.out.println("The avg of " + Arrays.toString(sumArray) + " is " + Arrays.stream(sumArray).average().getAsDouble());
}
}
Please note that the code itself does not contain any translation of the comments and string literals, as per your request.
英文:
Input Text File:
>Min: 1,2,3,5,6
>
>Max: 1,2,3,5,6
>
>Avg: 1,2,3,5,6
Get the MIN/MAX and SUM from the list of numbers in the text file.
package net.codejava;
import java.io.FileReader;
import java.util.Scanner;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Formatter;
public class MyFile {
public static int[] toIntArray(String input, String delimiter) {
return Arrays.stream(input.split(delimiter)).mapToInt(Integer::parseInt).toArray();
}
public static void main(String[] args) throws FileNotFoundException {
//Declare Variables
int min = Integer.MAX_VALUE;
int max = Integer.MIN_VALUE;
double avg = 0.0;
int sum = 0;
int count = 0;
String[] numArray = new String[30];
int[] maxArray;
int[] minArray;
int[] sumArray;
try {
//Read the text file ('input.txt')
String myFile = "input.txt";
Scanner input = new Scanner(new FileReader(myFile));
while(input.hasNext()) {
input.next();
numArray[count] = input.next();
count++;
}
} catch(FileNotFoundException e) {
System.out.println("File not found!");
}
minArray = toIntArray(numArray[0],",");
maxArray = toIntArray(numArray[1],",");
sumArray = toIntArray(numArray[2],",");
System.out.println(" Min Value " + Arrays.stream(minArray).min().getAsInt());
System.out.println(" Max Value " + Arrays.stream(maxArray).max().getAsInt());
System.out.println(" Sum Value " + Arrays.stream(sumArray).sum());
}
}
Desired Output:
>The min of [1, 2, 3, 5, 6] is 1
>
>The min of [1, 2, 3, 5, 6] is 6
>
>The avg of [1, 2, 3, 5, 6] is 3.4
Current Output:
Exception in thread "main" java.util.NoSuchElementException
at java.base/java.util.Scanner.throwFor(Scanner.java:937)
at java.base/java.util.Scanner.next(Scanner.java:1478)
at net.codejava.MyFile.main(MyFile.java:32)
答案1
得分: 1
以下是翻译好的部分：
也许使用 Arrays.stream 方法解决这个问题的最简单方式如下：
文件格式：
最小值：1,2,3,5,6
最大值：1,2,7,5,6
平均值：1,2,3,5,6
Java 代码：
package org.personal.TestProject;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Scanner;
import java.io.FileReader;
public final class MinMaxAvg {
public static int[] toIntArray(String input, String delimiter) {
return Arrays.stream(input.split(delimiter))
.mapToInt(Integer::parseInt)
.toArray();
}
public static void main(String[] args) throws FileNotFoundException {
//声明变量
int min ;
int max ;
double avg ;
int sum;
int count = 0;
String[] numArray = new String[3];
int[] maxArray;
int[] minArray;
int[] sumArray;
//读取文本文件（'input.txt'）
String fileName = "input.txt";
Scanner input = new Scanner(new FileReader(fileName));
//读取数字。获取计数。
while (input.hasNext()) {
numArray[count] = input.next();
count++;
}
// 将逗号分隔的字符串转换为整数数组，同时从字符串中移除 Min:、Max: 和 Avg: 模式
minArray = toIntArray(numArray[0].replaceAll("Min:",""),",");
maxArray = toIntArray(numArray[1].replaceAll("Max:",""),",");
sumArray = toIntArray(numArray[2].replaceAll("Avg:",""),",");
// 使用 arrays.stream 来查找最小值、最大值、总和和平均值。最后一行生成总和和平均值
min = Arrays.stream(minArray).min().getAsInt();
max = Arrays.stream(maxArray).max().getAsInt();
sum = Arrays.stream(sumArray).sum();
avg = Arrays.stream(sumArray).average().getAsDouble();
System.out.println(" 最小值 " + min);
System.out.println(" 最大值 " + max);
System.out.println(" 总和 " + sum);
System.out.println(" 平均值 " + avg);
}
}
输出如下：
最小值 1
最大值 7
总和 17
平均值 3.4
英文:
Perhaps one of the simplest way of solving this using Arrays.stream method is below,
File Format :
Min:1,2,3,5,6
Max:1,2,7,5,6
Avg:1,2,3,5,6
Java code :
package org.personal.TestProject;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Scanner;
import java.io.FileReader;
public final class MinMaxAvg {
public static int[] toIntArray(String input, String delimiter) {
return Arrays.stream(input.split(delimiter))
.mapToInt(Integer::parseInt)
.toArray();
}
public static void main(String[] args) throws FileNotFoundException {
//Declare Variables
int min ;
int max ;
double avg ;
int sum;
int count = 0;
String[] numArray = new String[3];
int[] maxArray;
int[] minArray;
int[] sumArray;
//Read the text file ('input.txt')
String fileName = "input.txt";
Scanner input = new Scanner(new FileReader(fileName));
//Read the numbers. Get count.
while (input.hasNext()) {
numArray[count] = input.next();
count++;
}
// Convert the comma seperated string to Int array after removing Min:, Max: and Avg: pattern from the string
minArray = toIntArray(numArray[0].replaceAll("Min:",""),",");
maxArray = toIntArray(numArray[1].replaceAll("Max:",""),",");
sumArray = toIntArray(numArray[2].replaceAll("Avg:",""),",");
// Use arrays.stream to find min,max,sum and average. Sum and average is generated for last line
min = Arrays.stream(minArray).min().getAsInt();
max = Arrays.stream(maxArray).max().getAsInt();
sum = Arrays.stream(sumArray).sum();
avg = Arrays.stream(sumArray).average().getAsDouble();
System.out.println(" Min Value " + min);
System.out.println(" Max Value " + max);
System.out.println(" Sum Value " + sum);
System.out.println(" Average Value " + avg);
}
}
Output is below,
Min Value 1
Max Value 7
Sum Value 17
Average Value 3.4
答案2
得分: 1
package MyFile;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.Arrays;
import java.io.PrintWriter;
public class MinMaxAvg {
public static void main(String[] args) {
// Create File object
try {
File fileName = new File("input.txt");
File output = new File("output.txt");
//Create Scanner to read file
Scanner scnr = new Scanner(fileName);
//Output the file line by line
PrintWriter writer = new PrintWriter(output);
//Read each line of file using Scanner class
while (scnr.hasNextLine()) {
String line = scnr.nextLine();
// split the line and place them in an array.
int[] numList = splitString(line);
if (line.toLowerCase().startsWith("min")) {
getMin(numList, writer);
} else if (line.toLowerCase().startsWith("max")) {
getMax(numList, writer);
} else if (line.toLowerCase().startsWith("avg")) {
getAverage(numList, writer);
} else if (line.toLowerCase().startsWith("p")) {
getPercentile(numList, line, writer);
} else if (line.toLowerCase().startsWith("sum")) {
getSum(numList, writer);
}
}
writer.close();
} catch (FileNotFoundException e) {
System.out.println(e + "File not found");
return;
}
}
//End main class
// Class to split
public static int[] splitString(String line) {
// trim the blank spaces on the line
String shorterLine = line.substring(4).trim();
//split the string
String[] list = shorterLine.split(",");
int listLen = list.length;
// Create an array and iterate through the numbers list
int[] numList = new int[listLen];
for (int i = 0; i != listLen; i++) {
numList[i] = Integer.parseInt(list[i]);
}
return numList;
}
//Calculate the average number
public static void getAverage(int[] numList, PrintWriter writer) {
//calculate the sum of the array numbers
int sum = 0;
for (int i = 0; i < numList.length; i++) {
sum = sum + numList[i];
}
float average = sum / (float) numList.length;
// Write average number to file
writer.format("The average of " + Arrays.toString(numList) + " is %.1f\n", average);
}
//calculate the sum
public static void getSum(int[] numList, PrintWriter writer) {
// Iterate through the array
int sum = 0;
for (int i = 0; i < numList.length; i++) {
sum = sum + numList[i];
}
// Write sum to file
writer.println("The sum of " + Arrays.toString(numList) + " is " + sum);
}
// Get min number
public static void getMin(int[] numList, PrintWriter writer) {
int min = numList[0];
for (int i = 1; i < numList.length; i++) {
if (numList[i] < min) {
min = numList[i];
}
}
//Write to file
writer.println("The min of " + Arrays.toString(numList) + " is " + min);
}
// Get Max number
public static void getMax(int[] numList, PrintWriter writer) {
int max = numList[0];
for (int i = 1; i < numList.length; i++) {
if (numList[i] > max) {
max = numList[i];
}
}
//Write to file
writer.println("The max of " + Arrays.toString(numList) + " is " + max);
}
// Get percentile
public static void getPercentile(int[] numList, String line, PrintWriter writer) {
// sort the array
Arrays.sort(numList);
int parsedInteger = Integer.parseInt(line.substring(1, 3));
// cast to float and divide by 100 to get the percentile
float percentile = (float) parsedInteger / 100;
// Calculate the index position for percentile
// minus 1 to accommodate the fact that indexing is from 0
int indexPercentile = (int) (numList.length * percentile) - 1;
//Write to file
writer.format("The %.0f" + "th percentile of " + Arrays.toString(numList)
+ " is " + numList[indexPercentile] + "\n", percentile * 100);
}
}
英文:
package MyFile;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.Arrays;
import java.io.PrintWriter;
public class MinMaxAvg {
public static void main(String[] args) {
// Create File object
try {
File fileName = new File("input.txt");
File output = new File("output.txt");
//Create Scanner to read file
Scanner scnr = new Scanner(fileName);
//Output the file line by line
PrintWriter writer = new PrintWriter(output);
//Read each line of file using Scanner class
while (scnr.hasNextLine()) {
String line = scnr.nextLine();
// split the line and place them in an array.
int[] numList = splitString(line);
if (line.toLowerCase().startsWith("min")) {
getMin(numList, writer);
} else if (line.toLowerCase().startsWith("max")) {
getMax(numList, writer);
} else if (line.toLowerCase().startsWith("avg")) {
getAverage(numList, writer);
} else if (line.toLowerCase().startsWith("p")) {
getPercentile(numList, line, writer);
} else if (line.toLowerCase().startsWith("sum")) {
getSum(numList, writer);
}
}
writer.close();
} catch (FileNotFoundException e) {
System.out.println(e + "File not found" );
return;
}
}
//End main class
// Class to split
public static int[] splitString(String line) {
// trim the blank spaces on the line
String shorterLine = line.substring(4).trim();
//split the string
String[] list = shorterLine.split(",");
int listLen = list.length;
// Create an array and iterate through the numbers list
int[] numList = new int[listLen];
for (int i = 0; i != listLen; i++) {
numList[i] = Integer.parseInt(list[i]);
}
return numList;
}
//Calculate the average number
public static void getAverage(int[] numList, PrintWriter writer) {
//calculate the sum of the array numbers
int sum = 0;
for (int i = 0; i < numList.length; i++) {
sum = sum + numList[i];
}
float average = sum / numList.length;
// Write average number to file
writer.format("The average of " + Arrays.toString(numList) + " is %.1f\n", average);
}
//calculate the sum
public static void getSum(int[] numList, PrintWriter writer) {
// Iterate through the array
int sum = 0;
for (int i = 0; i < numList.length; i++) {
sum = sum + numList[i];
}
// Write sum to file
writer.println("The sum of " + Arrays.toString(numList) + " is " + sum);
}
// Get min number
public static void getMin(int[] numList, PrintWriter writer) {
int min = numList[0];
for (int i = 1; i < numList.length; i++) {
if (numList[i] < min) {
min = numList[i];
}
}
//Write to file
writer.println("The min of " + Arrays.toString(numList) + " is " + min);
}
// Get Max number
public static void getMax(int[] numList, PrintWriter writer) {
int max = numList[0];
for (int i = 1; i < numList.length; i++) {
if (numList[i] > max) {
max = numList[i];
}
}
//Write to file
writer.println("The max of " + Arrays.toString(numList) + " is " + max);
}
// Get percentile
public static void getPercentile(int[] numList, String line, PrintWriter writer) {
// sort the array
Arrays.sort(numList);
int parsedInteger = Integer.parseInt(line.substring(1, 3));
// cast to float and divide by 100 to get the percentile
float percentile = (float) parsedInteger / 100;
// Calculate the index position for percentile
// minus 1 to accommodate the fact that indexing is from 0
int indexPercentile = (int) (numList.length * percentile) - 1;
//Write to file
writer.format("The %.0f" + "th percentile of " + Arrays.toString(numList)
+ " is " + numList[indexPercentile] + "\n", percentile * 100);
}
}
答案3
得分: 1
你可以简单地使用 IntSummaryStatistics 来自 IntStream::summaryStatistics。
import java.io.*;
import java.util.*;
import java.util.stream.*;
public class Main {
public static void main(String[] args) {
IntSummaryStatistics statistics = intsFromStream(System.in)
.summaryStatistics();
System.out.printf("min: %d%nmax: %d%nsum: %d%navg: %.2f%n",
statistics.getMin(),
statistics.getMax(),
statistics.getSum(),
statistics.getAverage()
);
}
private static IntStream intsFromStream(InputStream in) {
Scanner scanner = new Scanner(in);
Spliterator<String> spliterator = Spliterators.spliterator(scanner, Long.MAX_VALUE, Spliterator.ORDERED | Spliterator.NONNULL);
return StreamSupport.stream(spliterator, false)
.onClose(scanner::close)
.mapToInt(Integer::valueOf);
}
}
英文:
You can simply use IntSummaryStatistics from an IntStream::summaryStatistics.
<!-- language-all: lang-java -->
import java.io.*;
import java.util.*;
import java.util.stream.*;
public class Main {
public static void main(String[] args) {
IntSummaryStatistics statistics = intsFromStream(System.in)
.summaryStatistics();
System.out.printf("min: %d%nmax: %d%nsum: %d%navg: %.2f%n",
statistics.getMin(),
statistics.getMax(),
statistics.getSum(),
statistics.getAverage()
);
}
private static IntStream intsFromStream(InputStream in) {
Scanner scanner = new Scanner(in);
Spliterator<String> spliterator = Spliterators.spliterator(scanner, Long.MAX_VALUE, Spliterator.ORDERED | Spliterator.NONNULL);
return StreamSupport.stream(spliterator, false)
.onClose(scanner::close)
.mapToInt(Integer::valueOf);
}
}
TIO-kcmirsew: https://tio.run/##dVJrSwJBFP3ur7gEwho2kFEfNANJA8EHuBlBRNx0XMZ2ZpaZu5tS/nabfeUmuV/m7jnnvs7MGhO8WC8/9nshI20I1g5gQrPzTq2KxCTCfzFLhqNMqSh@D8UCFiFaC2MUCr5qAAVqCckdiRZLkI7zfDJCBS@vgCawjUwKMFTkx1Ki2fqp3roUm6fmYReEIvtgtPSztp6/tcQlE6qR5acfs8cVvEYnYwuxjolFrjmtvDMpVBvqy7qSuMkDl50HmAQuYK1VXZ01f6sfhmEBp7FbpHGSxM1p0q15muwl3GDAvXKpbP5daqYRCRIv3Uztynw4tmWoovhAle76C1SKG7DF2QXFP0vUc7rCpigU5AYgbW7zW7oDe8BcWkVhWYXyispNGGkVsHHv@e2pN5oPmtUMNp31B7NBH77/oJPpZDIfjYoZDKfYKMhX8OMofXTFU/MqDZuwwtDyyuVrdR9qy8tJ2u1F@lsRSIwetTPOeUQ8SBUJhjGfrgqTd/v9JbTgCq7h5gc "Java (JDK) – Try It Online"
答案4
得分: 0
当阅读和写入文件时，请务必在处理完成后始终关闭资源。您可以找到多种方法来做到这一点。有关处理资源的信息，请参阅 https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html。
File fileName = new File("input.txt");
try (FileReader fileReader = new FileReader(fileName);
BufferedReader bufferedReader = new BufferedReader(fileReader);) {
String input = bufferedReader.readLine();
while (input != null) {
//做一些操作... 文本文件将是字符串类型。
input = bufferedReader.readLine();
}
} catch (FileNotFoundException e) {
System.out.println("文件未找到 " + fileName.getName());
} catch (IOException e) {
System.out.println("处理文件时出错 " + fileName.getName());
}
英文:
When reading and writing too and from files be sure to always close the resource when processing has finished. You can find multiple ways to do this. See https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html for information on handling resources.
File fileName = new File("input.txt");
try(FileReader fileReader = new FileReader(fileName);
BufferedReader bufferedReader = new BufferedReader(fileReader);){
String input = bufferedReader.readLine();
while(input != null) {
//Do something... text file will be of type String.
input = bufferedReader.readLine();
}
} catch (FileNotFoundException e){
System.out.println("File not found " + fileName.getName());
} catch (IOException e) {
System.out.println("Error processing file " + fileName.getName());
}
答案5
得分: 0
你可以将 while 循环中的条件替换为：while (input.hasNext()) {，然后在之后检查输入是否为整数。
英文:
You could replace the condition in the while loop with: while(input.hasNext()) { and check after if the input is an int
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