Question

我正在尝试在线解决一些面试问题。我需要帮助理解这一行。 board[i][j]='#';有人可以向我解释一下吗？感谢

public static boolean exist(char[][] board, String word) {
        int m = board.length;
        int n = board[0].length;

        boolean result = false;
        for(int i=0; i<m; i++){
            for(int j=0; j<n; j++){
               if(dfs(board,word,i,j,0)){
                   result = true;
               }
            }
        }

        return result;
    }

    public static boolean dfs(char[][] board, String word, int i, int j, int k){
        int m = board.length;
        int n = board[0].length;

        if(i<0 || j<0 || i>=m || j>=n){
            return false;
        }

        if(board[i][j] == word.charAt(k)){
            char temp = board[i][j];
            board[i][j]='#';
            if(k==word.length()-1){
                return true;
            }else if(dfs(board, word, i-1, j, k+1)
            ||dfs(board, word, i+1, j, k+1)
            ||dfs(board, word, i, j-1, k+1)
            ||dfs(board, word, i, j+1, k+1)){
                return true;
            }
            board[i][j]=temp;
        }

        return false;
    }

Answer 1

'board'是一个二维数组。每次迭代板以避免重新访问已访问过的节点时，它们已经为访问节点分配了一些值。（即。[i] [j] =“＃”）。您可以在“＃”（仅表示其访问过）中使用任何字符

Answer 2

在java中你几乎没有数组的例子：o）

因此，board[i][j]='#'只是将#设置为名为[i,j]
的数组变量的board位置

    //one dimensional array with 10 values
    char[] oneDimArray = new char[10];

    for (int i = 0; i < oneDimArray.length; i++) {
        //i works as index, set value at index "i" as follow- ascii table "48" equals to zero :o)
        oneDimArray[i]= (char) (48+i);
    }

    for (int i = 0; i < oneDimArray.length; i++) {
        //i works as index, actual value you will get as follow
        System.out.println("value @ " + i + ": "+  oneDimArray[i]+ " ");
    }

    System.out.println("===");

    //two dim array - i x j = 10x5 values
    String[][] twoDimArray = new String[10][5];
    //iterate over first index- 'i' - eg. row
    for (int i = 0; i < twoDimArray.length; i++) {
        //iterate over second index- 'j' - eg. column
        for (int j = 0; j < twoDimArray[i].length; j++) {
            //fill @ index [i,j]
            twoDimArray[i][j] = "[" + i + ";" + j+"]";
        }
    }

    for (int i = 0; i < twoDimArray.length; i++) {
        //iterate over second index- 'j' - eg. column
        for (int j = 0; j < twoDimArray[i].length; j++) {
            //and read
            System.out.println("value @ " + i +"," + j + ": " + twoDimArray[i][j]);
        }
        System.out.println();
    }

您将获得如下输出：

value @ 0: 0 
value @ 1: 1 
value @ 2: 2 
value @ 3: 3 
value @ 4: 4 
value @ 5: 5 
value @ 6: 6 
value @ 7: 7 
value @ 8: 8 
value @ 9: 9 
===
value @ 0,0: [0;0]
value @ 0,1: [0;1]
value @ 0,2: [0;2]
value @ 0,3: [0;3]
value @ 0,4: [0;4]

value @ 1,0: [1;0]
value @ 1,1: [1;1]
value @ 1,2: [1;2]
value @ 1,3: [1;3]
value @ 1,4: [1;4]

value @ 2,0: [2;0]
value @ 2,1: [2;1]
value @ 2,2: [2;2]
value @ 2,3: [2;3]
value @ 2,4: [2;4]

value @ 3,0: [3;0]
value @ 3,1: [3;1]
value @ 3,2: [3;2]
value @ 3,3: [3;3]
value @ 3,4: [3;4]

value @ 4,0: [4;0]
value @ 4,1: [4;1]
value @ 4,2: [4;2]
value @ 4,3: [4;3]
value @ 4,4: [4;4]

value @ 5,0: [5;0]
value @ 5,1: [5;1]
value @ 5,2: [5;2]
value @ 5,3: [5;3]
value @ 5,4: [5;4]

value @ 6,0: [6;0]
value @ 6,1: [6;1]
value @ 6,2: [6;2]
value @ 6,3: [6;3]
value @ 6,4: [6;4]

value @ 7,0: [7;0]
value @ 7,1: [7;1]
value @ 7,2: [7;2]
value @ 7,3: [7;3]
value @ 7,4: [7;4]

value @ 8,0: [8;0]
value @ 8,1: [8;1]
value @ 8,2: [8;2]
value @ 8,3: [8;3]
value @ 8,4: [8;4]

value @ 9,0: [9;0]
value @ 9,1: [9;1]
value @ 9,2: [9;2]
value @ 9,3: [9;3]
value @ 9,4: [9;4]

请帮我理解这段代码中的一行

2 个答案: