java - ideone 上线程 "main"java.util.NoSuchElementException 中的异常

Question

这是我在 Ideone 上测试时使用 java 编写的第一个代码。它显示:

Exception in thread "main" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Scanner.java:862)
    at java.util.Scanner.next(Scanner.java:1485)
    at java.util.Scanner.nextInt(Scanner.java:2117)
    at java.util.Scanner.nextInt(Scanner.java:2076)
    at Hw2_p4.main(Main.java:22)

我搜索了答案，但没有找到问题的原因或解决方法。代码在eclipse上正常运行

这是代码

import java.util.Scanner;

class Hw2_p4 {

    static void swap(String[] A, int a, int b) {
        String temp = A[a];
        A[a] = A[b];
        A[b] = temp;
    }

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt(), m = sc.nextInt();
        int i, j, k, l, counter = 0;

        String[] name = new String[16];
        String[][] notalong = new String[120][2];
        String[] temp = new String[120];
        boolean[][] A = new boolean[120][2];

        for (i = 0; i < n; i++) {
            name[i] = sc.next();
        }

        for (i = 0; i < m; i++) {
            for (j = 0; j < 2; j++) {
                notalong[i][j] = sc.next();
            }
        }

        int flag = 0;

        for (i = 0; i < m; i++) {
            for (j = 0; j < 2; j++) {
                flag = 0;
                for (k = i + 1; k < m; k++) {
                    for (l = 0; l < 2; l++) {
                        if (notalong[i][j].compareToIgnoreCase(notalong[k][l]) == 0 && A[i][j] == false && A[k][l] == false) {
                            A[k][l] = true;
                            flag = 1;
                        }
                    }
                }

                if (flag == 1) {
                    A[i][j] = true;
                    counter++;
                } else if (flag == 0 && A[i][0] == false && A[i][1] == false) {
                    A[i][j] = true;
                    counter++;
                }
            }

        }

        System.out.println(n - counter);
        int x = 0;

        for (i = 0; i < m; i++) {
            for (j = 0; j < 2; j++) {
                if (A[i][j] == false) {
                    temp[x++] = notalong[i][j];
                    A[i][j] = true;

                    for (k = i + 1; k < m; k++) {
                        for (l = 0; l < 2; l++) {
                            if (notalong[i][j].compareToIgnoreCase(notalong[k][l]) == 0 && A[k][l] == false) {
                                A[k][l] = true;
                            }
                        }
                    }
                }
            }
        }

        //compare not along with names
        int found = 1;

        for (i = 0; i < n; i++) {
            found = 0;
            for (j = 0; j < m; j++) {
                for (k = 0; k < 2; k++) {
                    if (name[i].compareToIgnoreCase(notalong[j][k]) == 0) {
                        found = 1;
                    }
                }
            }

            if (found == 0) {
                temp[x++] = name[i];
            }
        }

        //sorting lexicographically
        boolean swapp = true;
        for (i = 0; i < x && swapp; i++) {
            swapp = false;
            for (j = 0; j < x - i - 1; j++) {
                if (temp[j].compareToIgnoreCase(temp[j + 1]) > 0) {
                    swap(temp, j, j + 1);
                    swapp = true;
                }
            }
        }

        for (i = 0; i < x; i++) {
            System.out.println(temp[i]);
        }
    }
}

Answer 1

Ideone 不是交互式的。在运行应用程序之前，您必须单击 Specify input 并在其中输入所有输入。您看到的是异常情况，因为 System.in 处于“文件结束”状态。