英文:
How do i change my array from being on 1 line to being a 20x20 square? (Java)
问题
public class MyGrid {
public static void main(String[] args) throws IOException {
FileReader file = new FileReader("list.txt");
int[][] grid = new int[20][20];
int row = 0;
int col = 0;
try {
Scanner input = new Scanner(file);
while (input.hasNext()) {
grid[row][col] = input.nextInt();
col++;
if (col == 20) {
col = 0;
row++;
}
}
input.close();
} catch (Exception e) {
e.printStackTrace();
}
for (int[] rowArray : grid) {
System.out.println(Arrays.toString(rowArray));
}
}
}
英文:
I need to change how my array is formatted to where it shows as a 20x20 square. Any ideas on best way to do this?
public class MyGrid {
public static void main(String[] args) throws IOException
{
FileReader file = new FileReader("list.txt");
int[] integers = new int [400];
int i=0;
try {
Scanner input = new Scanner(file);
while(input.hasNext())
{
integers[i] = input.nextInt();
i++;
}
input.close();
}
catch(Exception e)
{
e.printStackTrace();
}
System.out.println(Arrays.toString(integers));
}
}
答案1
得分: 1
try-with-resources 语句 很不错；我建议充分利用它来进行安全的清理。我认为不需要使用 FileReader，只用 File 就足够了。然后，每当有 20 个值时，打印一个换行，否则打印一个空格；然后打印该值。代码如下：
int[] integers = new int[400];
try (Scanner input = new Scanner(new File("list.txt"))) {
int i = 0;
while (input.hasNextInt()) {
integers[i] = input.nextInt();
if (i != 0) {
if (i % 20 == 0) {
System.out.println();
} else {
System.out.print(" ");
}
}
System.out.printf("%03d", integers[i]);
i++;
}
} catch (Exception e) {
e.printStackTrace();
}
英文:
The try-with-resources statement is nice; I suggest taking advantage of it to clean-up safely. I don't see any need for a FileReader with your Scanner (File is good enough). Then every 20 values you print a newline - otherwise print a space; then print the value. Like,
int[] integers = new int[400];
try (Scanner input = new Scanner(new File("list.txt"))) {
int i = 0;
while (input.hasNextInt()) {
integers[i] = input.nextInt();
if (i != 0) {
if (i % 20 == 0) {
System.out.println();
} else {
System.out.print(" ");
}
}
System.out.printf("%03d", integers[i]);
i++;
}
} catch (Exception e) {
e.printStackTrace();
}
答案2
得分: 0
以下是翻译好的内容：
最简单且最快速的方法（对我来说）是：
public class MyGrid {
public static void main(String[] args) throws IOException {
FileReader file = new FileReader("list.txt");
int[] integers = new int[400];
int[][] table = new int[20][20];
int m, n, i = 0;
int tableWidth = table[0].length; // 在这种情况下为 20
try {
Scanner input = new Scanner(file);
while(input.hasNext()) {
int value = input.nextInt();
integers[i] = value;
m = i / tableWidth; // 行索引
n = i % tableWidth; // 列索引
table[m][n] = value;
i++;
}
input.close();
} catch(Exception e) {
e.printStackTrace();
}
System.out.println(Arrays.toString(integers));
}
}
此外，此代码将适应任何其他表格大小（例如 500、600 或 4237 个元素）。
**注意：** 此代码将会在一个二维数组中**存储数据**，但不会在控制台中显示。如果您想要在读取文件时显示数据，我建议您查看适应性更强的 **@Elliott Frisch** 的答案。
英文:
The simplest and fastest way to do this (for me) would be that:
public class MyGrid {
public static void main(String[] args) throws IOException {
FileReader file = new FileReader("list.txt");
int[] integers = new int[400];
int[][] table = new int[20][20];
int m, n, i = 0;
int tableWidth = table[0].length; // 20 in that case
try {
Scanner input = new Scanner(file);
while(input.hasNext()) {
int value = input.nextInt();
integers[i] = value;
m = i / tableWidth; // Row index
n = i % tableWidth; // Column index
table[m][n] = value;
i++;
}
input.close();
} catch(Exception e) {
e.printStackTrace();
}
System.out.println(Arrays.toString(integers));
}
}
Moreover, this code will adapt to any other table size (e.g. 500, 600 or 4237 elements).
CAUTION: this code will store data in a 2D array but it will not display it in the console. If you want to display data while reading file, I suggest you to look at @Elliott Frisch answer which is more adapted.
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