java.util.Scanner 处的 java.util.NoSuchElementException

Question

我正在 HackerEarth 解决问题，我无法弄清楚为什么我的程序在命令行上正确运行并给出正确的结果，但在代码编辑器上运行时却给出 java.util.NoSuchElementException 异常。

我搜索过但无法解决。

import java.util.Scanner;

public class TestClass {
    public static int[][] arr = null;
    public static int[][] dp = null;

    public static void main(String[] args) {
        int N, M, T;
        int min;
        int count = 0;
        Scanner scan = new Scanner(System.in);

        N = scan.nextInt();
        M = scan.nextInt();

        arr = new int[N][M];
        dp = new int[N + 1][M + 1];

        for (int i = 0; i < N; ++i) {
            for (int j = 0; j < M; ++j) {
                arr[i][j] = scan.nextInt();   //line 26
            }
        }

        for (int i = 0; i < M + 1; ++i)
            dp[0][i] = 0;

        for (int i = 0; i < N + 1; ++i)
            dp[i][0] = 0;

        for (int i = 1; i < N + 1; ++i) {
            for (int j = 1; j < M + 1; ++j) {
                if (arr[i - 1][j - 1] == 0) {
                    min = Math.min(dp[i - 1][j], Math.min(dp[i]
                        [j - 1], dp[i - 1][j - 1]));
                    dp[i][j] = min + 1;
                } else
                    dp[i][j] = 0;
            }
        }

        count = 0;
        for (int i = 1; i < N + 1; ++i) {
            for (int j = 1; j < M + 1; ++j) {
                if (dp[i][j] != 0)
                    count += dp[i][j];
            }
        }
        System.out.println("" + count);
    }//main
}//class

异常(exception):

Exception in thread "main" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Scanner.java:907)
    at java.util.Scanner.next(Scanner.java:1530)
    at java.util.Scanner.nextInt(Scanner.java:2160)
    at java.util.Scanner.nextInt(Scanner.java:2119)
    at TestClass.main(editor_trsource_1429355115_85417.java:26)

Answer 1

这意味着您没有来自标准输入的数据，并且您正在尝试从中获取nextInt。您可能应该使用 hasNextInt 检查是否有数据可供消费者使用像:

if (scanner.hasNextInt()) {
   //read nextInt();
}