阅读txt文件到二维数组 [英] Read .txt file into 2D Array
问题描述
有几个这些主题在那里，但这个问题有一个轻微的扭曲，它使不同。
There are a few of these topics out there, but this problem has a slight twist that makes it different.
我只集中在一个更大的问题的一半。我相信很多人都知道的幻方的问题。
I'm focused on only half of a larger problem. I'm sure many of you are aware of the magic square problem.
提示：结果
假设有像所示的方形各行线和数字文件。编写一个程序，读取信息到整数的二维数组。该计划应确定矩阵是一个幻方或没有。
Prompt:
Assume a file with lines and numbers on each line like the square shown. Write a program that reads info into a two dimensional array of intS. The program should determine if the matrix is a magic square or not.
工作方案：
public static int[][] create2DIntMatrixFromFile(String filename) throws Exception {
int[][] matrix = {{1}, {2}};
File inFile = new File(filename);
Scanner in = new Scanner(inFile);
int intLength = 0;
String[] length = in.nextLine().trim().split("\\s+");
for (int i = 0; i < length.length; i++) {
intLength++;
}
in.close();
matrix = new int[intLength][intLength];
in = new Scanner(inFile);
int lineCount = 0;
while (in.hasNextLine()) {
String[] currentLine = in.nextLine().trim().split("\\s+");
for (int i = 0; i < currentLine.length; i++) {
matrix[lineCount][i] = Integer.parseInt(currentLine[i]);
}
lineCount++;
}
return matrix;
}
public static boolean isMagicSquare(int[][] square) {
return false;
}
下面是我的（旧）code读取从文本文件信息到一个二维数组：
Here is my (old) code for reading info from a text file into a 2D array:
public static int[][] create2DIntMatrixFromFile(String filename) throws Exception {
int[][] matrix = {{1}, {2}};
File inFile = new File(filename);
Scanner in = new Scanner(inFile);
in.useDelimiter("[/n]");
String line = "";
int lineCount = 0;
while (in.hasNextLine()) {
line = in.nextLine().trim();
Scanner lineIn = new Scanner(line);
lineIn.useDelimiter("");
for (int i = 0; lineIn.hasNext(); i++) {
matrix[lineCount][i] = Integer.parseInt(lineIn.next());
lineIn.next();
}
lineCount++;
}
return matrix;
}
public static boolean isMagicSquare(int[][] square) {
return false;
}
这里是文本文件，我从读书。它是在一个9×9的2D阵列的形状，但该方案必须适应暧昧大小的阵列。
And here is the text file I am reading from. It is in the shape of a 9x9 2D array, but the program must accommodate an array of ambiguous size.
37 48 59 70 81 2 13 24 35
36 38 49 60 71 73 3 14 25
26 28 39 50 61 72 74 4 15
16 27 29 40 51 62 64 75 5
6 17 19 30 41 52 63 65 76
77 7 18 20 31 42 53 55 66
67 78 8 10 21 32 43 54 56
57 68 79 9 11 22 33 44 46
47 58 69 80 1 12 23 34 45
有两个空格出发故意每一行。
There are two spaces proceeding each line on purpose.
在我说出确切的问题，这是一个家庭作业模板，这样的方法声明和变量初始化为pre-确定。
Before I state the exact problem, this is a homework template so the method declaration and variable initialization was pre-determined.
我还不能肯定，该方法能够正确创建了文件中的二维数组，因为我不能运行它。的问题是，由于某种原因，矩阵用1柱和2行初始化。是什么原因我不知道，但为了从文件中填充的数字数组我需要创建一个尺寸等于值的行数的二维数组。
I'm not positive that the method even correctly creates a 2D Array from the file because I can't run it yet. The issue is that for some reason "matrix" was initialized with 1 column and 2 rows. For what reason I'm not sure, but in order to fill an array with the numbers from the file I need to create a 2D array with dimensions equal to the number of values in a line.
我previously写了code创建一个新的二维数组
I previously had written code to create a new 2D array
int[line.length()][line.length()]
但它创造了一个36X36阵列，因为这是许多单个字符如何在一行。我有一种感觉它是通过第一线循环并具有计数保持一个零分隔的数字的每个序列的轨迹一样简单。
but it created a 36x36 array because that's how many individual characters are in one line. I have a feeling it's as simple as looping through the first line and having a counter keep track of each sequence of numbers separated by a zero.
对于我来说，解决方案似乎过于低效和费时只是为了找到新的阵列的尺寸。什么是实现这一目标的最佳途径？如果不使用的ArrayList，因为我有利用的ArrayList后重写这个计划。
To me, that solution seems too inefficient and time consuming just to find the dimensions of the new array. What's the best way to accomplish this? Without using ArrayLists as I have to rewrite this program after using ArrayLists.
推荐答案
我公司生产，从您提供的文件中有如下二维数组：
I produced the following 2D array from the file you provided:
37 | 48 | 59 | 70 | 81 | 2 | 13 | 24 | 35
----+----+----+----+----+----+----+----+----
36 | 38 | 49 | 60 | 71 | 73 | 3 | 14 | 25
----+----+----+----+----+----+----+----+----
26 | 28 | 39 | 50 | 61 | 72 | 74 | 4 | 15
----+----+----+----+----+----+----+----+----
16 | 27 | 29 | 40 | 51 | 62 | 64 | 75 | 5
----+----+----+----+----+----+----+----+----
6 | 17 | 19 | 30 | 41 | 52 | 63 | 65 | 76
----+----+----+----+----+----+----+----+----
77 | 7 | 18 | 20 | 31 | 42 | 53 | 55 | 66
----+----+----+----+----+----+----+----+----
67 | 78 | 8 | 10 | 21 | 32 | 43 | 54 | 56
----+----+----+----+----+----+----+----+----
57 | 68 | 79 | 9 | 11 | 22 | 33 | 44 | 46
----+----+----+----+----+----+----+----+----
47 | 58 | 69 | 80 | 1 | 12 | 23 | 34 | 45
阵列计算出的平方的大小时，它读取该文件的第一行。这是非常有活力。其作品只要输入文件是一个完美的正方形。我没有更多的错误处理。
The array figures out the size of the square when it reads the first line of the file. This is very dynamic. Its works as long as the input file is a perfect square. I have no further error handling.
下面是一个简单的做法，要坚持你的指导方针。
Here is a simple approach which should adhere to your guidelines.
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
public class ReadMagicSquare {
public static int[][] create2DIntMatrixFromFile(String filename) throws Exception {
int[][] matrix = null;
// If included in an Eclipse project.
InputStream stream = ClassLoader.getSystemResourceAsStream(filename);
BufferedReader buffer = new BufferedReader(new InputStreamReader(stream));
// If in the same directory - Probably in your case...
// Just comment out the 2 lines above this and uncomment the line
// that follows.
//BufferedReader buffer = new BufferedReader(new FileReader(filename));
String line;
int row = 0;
int size = 0;
while ((line = buffer.readLine()) != null) {
String[] vals = line.trim().split("\\s+");
// Lazy instantiation.
if (matrix == null) {
size = vals.length;
matrix = new int[size][size];
}
for (int col = 0; col < size; col++) {
matrix[row][col] = Integer.parseInt(vals[col]);
}
row++;
}
return matrix;
}
public static void printMatrix(int[][] matrix) {
String str = "";
int size = matrix.length;
if (matrix != null) {
for (int row = 0; row < size; row++) {
str += " ";
for (int col = 0; col < size; col++) {
str += String.format("%2d", matrix[row][col]);
if (col < size - 1) {
str += " | ";
}
}
if (row < size - 1) {
str += "\n";
for (int col = 0; col < size; col++) {
for (int i = 0; i < 4; i++) {
str += "-";
}
if (col < size - 1) {
str += "+";
}
}
str += "\n";
} else {
str += "\n";
}
}
}
System.out.println(str);
}
public static void main(String[] args) {
int[][] matrix = null;
try {
matrix = create2DIntMatrixFromFile("square.txt");
} catch (Exception e) {
e.printStackTrace();
}
printMatrix(matrix);
}
}
这方法更完善和优化。
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class ReadMagicSquare {
private int[][] matrix;
private int size = -1;
private int log10 = 0;
private String numberFormat;
public ReadMagicSquare(String filename) {
try {
readFile(filename);
} catch (IOException e) {
e.printStackTrace();
}
}
public void readFile(String filename) throws IOException {
// If included in an Eclipse project.
InputStream stream = ClassLoader.getSystemResourceAsStream(filename);
BufferedReader buffer = new BufferedReader(new InputStreamReader(stream));
// If in the same directory - Probably in your case...
// Just comment out the 2 lines above this and uncomment the line
// that follows.
//BufferedReader buffer = new BufferedReader(new FileReader(filename));
String line;
int row = 0;
while ((line = buffer.readLine()) != null) {
String[] vals = line.trim().split("\\s+");
// Lazy instantiation.
if (matrix == null) {
size = vals.length;
matrix = new int[size][size];
log10 = (int) Math.floor(Math.log10(size * size)) + 1;
numberFormat = String.format("%%%dd", log10);
}
for (int col = 0; col < size; col++) {
matrix[row][col] = Integer.parseInt(vals[col]);
}
row++;
}
}
@Override
public String toString() {
StringBuffer buff = new StringBuffer();
if (matrix != null) {
for (int row = 0; row < size; row++) {
buff.append(" ");
for (int col = 0; col < size; col++) {
buff.append(String.format(numberFormat, matrix[row][col]));
if (col < size - 1) {
buff.append(" | ");
}
}
if (row < size - 1) {
buff.append("\n");
for (int col = 0; col < size; col++) {
for (int i = 0; i <= log10 + 1; i++) {
buff.append("-");
}
if (col < size - 1) {
buff.append("+");
}
}
buff.append("\n");
} else {
buff.append("\n");
}
}
}
return buff.toString();
}
public static void main(String[] args) {
ReadMagicSquare square = new ReadMagicSquare("square.txt");
System.out.println(square.toString());
}
}
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