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06.10.2019
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Again, the solution gives me the correct output but it cannot pass the verification

Question about the task

Under discussion

I get the correct output but it cannot pass the verification. I'm getting crazy with these non-solvable tasks. Someone please help me.

1. We have a two-dimensional array that contains lowercase letters.
2. The detectAllWords method must find all the words in the wordSearch array.
3. The element(startX, startY) must correspond to the first letter of the word, while the element(endX, endY) corresponds to the last letter.
text is the word itself, located between the start and end elements
4. All the words are in the array.
5. The words can be arranged horizontally, vertically, and diagonally, both forward and backward.
6. The main method is not tested.

Requirements:

The Solution class must have a detectAllWords method.
The Solution class must contain a static Word class.
The Solution class must not have static fields.
The detectAllWords method must be static.
The detectAllWords method must be public.
The detectAllWords method should return the list of all words in the word search (according to the task conditions).

package com.codegym.task.task20.task2027; import java.util.ArrayList; import java.util.List; /* Word search */ public class Solution { public static void main(String[] args) { int[][] wordSearch = new int[][]{ {'f', 'd', 'e', 'r', 'l', 'e'}, {'u', 's', 'a', 'm', 'e', 'm'}, {'l', 'n', 'g', 'r', 'o', 'o'}, {'m', 'l', 'p', 'r', 'r', 'h'}, {'p', 'o', 'e', 'e', 'j', 'j'} }; detectAllWords(wordSearch, "home", "same"); /* Expected result home - (5, 3) - (2, 0) same - (1, 1) - (4, 1) */ } public static List<Word> detectAllWords(int[][] wordSearch, String... words) { List<Word> wordList = new ArrayList<>(); for (String word:words){ //Search for each word char firstLetter = word.charAt(0); wordLoop: for (int i = 0; i < wordSearch.length; i++){ for (int j = 0; j < wordSearch[i].length; j++){ if (firstLetter == wordSearch[i][j]){ List<Word> wrds = findWord(wordSearch, word, i, j); if (wrds != null){ wordList.addAll(wrds); break wordLoop; } } } } } System.out.println(wordList.toString()); return wordList; } private static List<Word> findWord(int[][] wTbl, String word, int x, int y){ List<Word> anotherList = new ArrayList<>(); int len = word.length() - 1; int a , b; StringBuilder sb = new StringBuilder(); //Loop 1 : Vertical Downward if(y + len <= wTbl[x].length){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a][b++]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x, y + len); anotherList.add(wrd); } } //Loop 2 : Diagonal Down-Right wise if(x + len <= wTbl.length && y + len <= wTbl[x].length){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a++][b++]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x + len, y + len); anotherList.add(wrd); } } //Loop 3 : Horizontal Right wise if(x + len <= wTbl.length){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a++][b]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x + len, y); anotherList.add(wrd); } } //Loop 4 : Diagonal Up-Right wise if(x + len <= wTbl.length && y - len >= 0){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a++][b--]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x + len, y - len); anotherList.add(wrd); } } //Loop 5 : Vertical Upward if(y - len >= 0){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a][b--]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x, y - len); anotherList.add(wrd); } } //Loop 6 : Diagonal Up-Left wise if(x - len >= 0 && y - len >= 0){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a--][b--]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x - len, y - len); anotherList.add(wrd); } } //Loop 7 : Horizontal Left wise if(x - len >= 0){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i <= len; i++){ sb.append((char) wTbl[a--][b]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x - len, y); anotherList.add(wrd); } } //Loop 8 : Diagonal Down-Left wise if(y + len <= wTbl[x].length && x - len >= 0){ a = x; b = y; sb = new StringBuilder(); for (int i = 0; i < len; i++){ sb.append(wTbl[a--][b++]); } if (sb.toString().equals(word)){ Word wrd = new Word(word); wrd.setStartPoint(x, y); wrd.setEndPoint(x - len, y + len); anotherList.add(wrd); } } return anotherList; } public static class Word { private String text; private int startX; private int startY; private int endX; private int endY; public Word(String text) { this.text = text; } public void setStartPoint(int i, int j) { startX = i; startY = j; } public void setEndPoint(int i, int j) { endX = i; endY = j; } @Override public String toString() { return String.format("%s - (%d, %d) - (%d, %d)", text, startX, startY, endX, endY); } } }

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Ian De Bie Full Stack Developer

7 November 2020, 17:25

this worked for me, hope it helps.

public static List<Word> detectAllWords(int[][] wordSearch, String... words) {
    List<Word> out = new ArrayList<>();
    int rows = wordSearch.length, cols = wordSearch[0].length;
    for (String s : words) {
        for (int i = 0; i < rows; ++i) {
            for (int j = 0; j < cols; ++j) {
                Word word = new Word("");
                if (wordSearch[i][j] == s.charAt(0)) word = checkCell(wordSearch, i, j, rows, cols, s);
                if (!word.text.equals("")) out.add(word);
            }
        }
    }
    return out;
}

private static Word checkCell(int[][] matrix, int x, int y, int rows, int cols, String s) {
    int len = s.length();
    for (int i = -1; i < 2; ++i) {
        for (int j = -1; j < 2; ++j) {
            if (i == 0 && j == 0) continue;
            int row = x + i, col = y + j, k;
            for (k = 1; k < len; ++k) {
                if (!isValid(row, col, rows, cols) || matrix[row][col] != s.charAt(k)) break;
                row += i;
                col += j;
            }
            if (k == len) {
                Word word = new Word(s);
                word.setStartPoint(y, x);
                word.setEndPoint(col - j, row - i);
                return word;
            }
        }
    }
    return new Word("");
}

private static boolean isValid(int row, int col, int rows, int cols) {
    return row >= 0 && row < rows && col >=0 && col < cols;
}

Guadalupe Gagnon

Level 37 , Tampa, United States

6 October 2019, 15:16

First, get rid of line 43, the task says it should return an arraylist, not output the values. You can do an output in the main method as that is not tested. The main problem that you are having is your coordinates are in reversed order. See below your answer against the correct answer Your solve: [same - (1, 1) - (1, 4), home - (3, 5) - (0, 2)] Correct solve: [same - (1, 1) - (4, 1), home - (5, 3) - (2, 0)]

Guadalupe Gagnon

Level 37 , Tampa, United States

6 October 2019, 15:19

Another problem is that your code is searching for words beyond the scope of the array. For example, I placed 'h', 'o' in one line of the array like this: {'m', 'e', 'g', 'r', 'h', 'o'} and your program tried to access the 5th element in that row, which threw an ArrayIndexOutOfBoundsException and crashed the program.

Hossein Shams

Level 26 , Atlanta, United States

6 October 2019, 16:07

Thank you for your reply. I moved that line to my main method. and tried to do the same change in my char array as you did. I didn't get any errors! And about the coordination, I think CodeGym has made a mistake. The coordination it's expecting is wrong. I tried to get the characters at the location which the code saves in a Word instance (I had to make the int values public for this). As it's noticeable in the first screenshot, it's giving the correct characters. I swapped the coordination values in all loops (x and y values) and I was not able to get the correct character any longer. Also even with all the changes, the code didn't pass the verification. first screenshot: before swapping coordinations

second screenshot: after swapping the coordinations

Guadalupe Gagnon

Level 37 , Tampa, United States

6 October 2019, 16:21

The coordinations that codegym uses and expects are x,y coordinates. The confusion that you are having is: 1) arrays start at index 0 2) to access a multidimensional array such as this the first number will be for the y axis and the second number for the x. This is backwards from standard x, y. Use the method that codegym expects (I highlighted below as well) Now I'm getting the out of bounds exception. on this array, so there is a bug in your code: 0 1 2 3 4 5 -------- x {'f', 'd', 'e', 'r', 'l', 'e'}, 0 {'u', 's', 'a', 'm', 'e', 'm'}, 1 {'l', 'n', 'g', 'r', 'h', 'o'}, 2 {'m', 'l', 'p', 'r', 'r', 'h'}, 3 {'p', 'o', 'e', 'e', 'j', 'j'} 4 y I added numbers to show you the x,y coordinates. 'home' starts at (5,3) and ends at (5,0) 'same' is (1,1) to (4,1)

Hossein Shams

Level 26 , Atlanta, United States

6 October 2019, 16:45

Again, I appreciate your replies to my post. With lots of respect, I have to disagree with you. When you define an array, the first coordination (or size) belongs to the outer array, while any other coordinations (or sizes at the time of definition) belong to inner arrays. when you define an array like this:

int[][] array = new int[4][3];

you will have an array of ints, which has four inner arrays, and each inner array will have 3 int elements. If you draw this array as a matrix, you can see the coordinations are alike to a real matrix: {{int[0][0], int[0][1], int[0][2]}, {int[1][0], int[1][1], int[1][2]}, {int[2][0], int[2][1], int[2][2]} {int[3][0], int[3][1], int[3][2]}} I still don't get it why are you getting an error, I tried to change characters in different ways, still no issues! Did you copy the whole code for the test or just a part of it?

Guadalupe Gagnon

Level 37 , Tampa, United States

7 October 2019, 03:53

Your array is set up exactly as mine, I am not contradicting you there. I am telling you that the task specifies that your answer should be in standard (x,y) format, and not array format [y][x]. If you do it (y, x) [which is how the array is set up], then you will fail. And yes, I copied all 202 lines of code and ran it. When I make no changes it runs fine, when I change the third array (wordSearch[2]) to: {'l', 'n', 'g', 'r', 'h', 'o'} <--- notice I changed the second to last character to 'h' it throws and array out of index error. So unless you have changed the code from above, there is a bug.

Hossein Shams

Level 26 , Atlanta, United States

8 October 2019, 21:55

You were right about the bug. Thank you. But the error I'm still getting is about the size of the output array. The list returned by detectAllWords is not the right size! I can change the toString method to get that Standard format for coordination. But I don't know why it's getting me an error about the logic of the code.

Guadalupe Gagnon

Level 37 , Tampa, United States

9 October 2019, 00:04

my code, when running the int[][] from yours (with home in it twice) did not find the second "home". It may be that codegym only wants your code to find the first occurrence of a word.

Hossein Shams

Level 26 , Atlanta, United States

9 October 2019, 00:12

I had a return command in every loop of findWord method first. Then I changed the code to find all other instances of the same word starting from the same location. and added them to an arraylist and returned the arraylist at the end of the method. So do you think I need to go back with that other solution? I mean one instance for every word?