提问人：Cheng Kai Hing Jacky 提问时间：11/12/2023 最后编辑：Cheng Kai Hing Jacky 更新时间：11/13/2023 访问量：58
如何在 java 中使用 Scanner 时使用空格键分隔新行和列
How to use space key to separate new rows and columns while using Scanner in java
问：
我正在制作这样的黑白棋游戏：
import java.util.Arrays;
import java.util.Scanner;
public class test{
public static Scanner sc = new Scanner(System.in);
public static void main(String[] args) {
System.out.print("Please enter the board size (4 or above and even number) : ");
int num = sc.nextInt();
int rows = num; // Number of rows
int cols = num; // Number of columns
if (num % 2 == 1 || num < 4) {
System.out.println("Error - input number should be 4 or above and even number.");
} else {
int[][] reversigame = new int[rows][cols];
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
System.out.print(reversigame[i][j] + " ");
}
reversigame[num - num / 2][num - num / 2] = 1;
reversigame[(num - num / 2) - 1][(num - num / 2) - 1] = 1;
reversigame[(num - num / 2)][(num - num / 2) - 1] = 2;
reversigame[(num - num / 2) - 1][(num - num / 2)] = 2;
System.out.println();
}
但我想在使用 Scanner 时使用空格键分隔新的行和列，如下所示：
System.out.print("Please enter the position of '1' (row col): ");
int bcp = sc.nextInt();//bcp=black chess place
int b = 1;//black chess = 1
String[] digits = String.valueOf(bcp).split(" ");
但是在我执行下一步时，它不能更改为行和列：
if (bcp > 5 || bcp < 0) {/*Control variables between 0 and 5*/
System.out.println("Error - input number should be 0 to 5!");
}
for (; reversigame[bcp + 1][bcp] == 2 || reversigame[bcp][bcp + 1] == 2 || reversigame[bcp - 1][bcp] == 2 || reversigame[bcp][bcp + 1] == 2;) {/*Check the black chess is or is't near the white chess*/
reversigame[bcp][bcp] = b;
System.out.println(Arrays.deepToString(reversigame));
if (reversigame[bcp + 1][bcp] != 2 || reversigame[bcp][bcp+ 1] != 2 || reversigame[bcp - 1][bcp] != 2 || reversigame[bcp][bcp + 1] != 2) {
System.out.println("Error - invalid move");
break;
}
}
那么，我应该如何在一个句子中添加行和列，同时使用空格键将它们分开呢？
答：
2赞
Alexey R.
11/12/2023
#1
你可以用空格分隔数字，并在一个序列中读取两个整数：
Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt();
int b = scanner.nextInt();
System.out.println("result = " + (a + b));
输出如下：
2 5
result = 7
0赞
Reilas
11/13/2023
#2
"...我想在使用 Scanner 时使用空格键分隔新行和列......”
只需调用 nextInt 两次。
int[] digits = { sc.nextInt(), sc.nextInt() };
如果需要 String 值，请使用 next 方法。
String[] digits = { sc.next(), sc.next() };
或者，使用 nextLine 方法，然后在空格字符上拆分。
String[] digits = sc.nextLine().split(" +");
0赞
Oleg Cherednik
11/13/2023
#3
您只需要使用两次。scan.nextInt()
public class Reversi {
private static final int WHITE = 1;
private static final int BLACK = 2;
private static final int ROW = 0;
private static final int COL = 1;
public static void main(String... args) {
Scanner scan = new Scanner(System.in);
int size = readBoardSize(scan);
int[][] board = new int[size][size];
int nextMove = WHITE;
printBoard(board);
while (true) {
int[] point = readNextMove(scan, nextMove, size);
int row = point[ROW];
int col = point[COL];
board[row][col] = nextMove;
printBoard(board);
nextMove = nextMove == WHITE ? BLACK : WHITE;
}
}
private static void printBoard(int[][] board) {
for (int row = 0; row < board.length; row++) {
for (int col = 0; col < board[row].length; col++) {
if (col > 0)
System.out.print(' ');
System.out.print(board[row][col]);
}
System.out.println();
}
}
private static int readBoardSize(Scanner scan) {
final int min = 4;
System.out.format("Please enter the board size (%d or above and even number): ", min);
int num = scan.nextInt();
if (num < min || num % 2 == 1) {
System.err.format("Input number should be %d or above and even number.\n", min);
throw new RuntimeException();
}
return num;
}
private static int[] readNextMove(Scanner scan, int nextMove, int size) {
final int min = 0;
System.out.format("Please enter the position of '%d' (row col): ", nextMove);
int row = scan.nextInt();
int col = scan.nextInt();
if (row < min || row >= size || col < min || col >= size) {
System.err.format("Input number should be between %d and %d.\n", min, size);
throw new RuntimeException();
}
int[] point = new int[2];
point[ROW] = row;
point[COL] = col;
return point;
}
}
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