public int find_cells(int[][] matrix, int row, int col) {
    if (row < 0 || col < 0 || row >= matrix.length || col >= matrix[0].length)
        return -1;
    boolean[][] visited = new boolean[matrix.length][matrix[0].length];
    int[] lr_neighbour = {0, 0, -1, 1};
    int[] tb_neighbour = {1, -1, 0, 0};
    int modified = 0;
    Queue<Integer> queue = new LinkedList<>();
    queue.add(matrix[row][col]);
    visited[row][col] = true;
    int current_cell = matrix[row][col];
    while (!queue.isEmpty()) {
        queue.remove();
        for (int index = 0; index < 4; index++) {
            int newRow = row + tb_neighbour[index];
            int newCol = col + lr_neighbour[index];
            if (newRow < 0 || newCol < 0 || newRow >= matrix.length || newCol >= matrix[0].length || visited[newRow][newCol])
                continue;
            if (current_cell == matrix[newRow][newCol]) {
                queue.add(matrix[newRow][newCol]);
                modified++;
            }
            visited[newRow][newCol] = true;
        }
    }
    return modified;
}

for (int index = 0;index < 4;index++){
    row = row+tb_neighbour[index];
    col = col+lr_neighbour[index];
}
假设 row = 2，col = 1...
然后在第一次迭代中，你这样做：row = 2 + 1 = 3，col = 1 + 0 = 1... 现在你的 row 和 col 值已经改变了...
在第二次迭代中，你得到：row = 3 + -1 = 2，col = 1 + 0 = 1... 这是错误的...
使用新变量并将 row 和 col 推入队列...
尝试使用以下内容：
```java
public int find_cells(int[][] matrix, int row, int col){
    //无效的行和列
    if (row < 0 || col < 0 || row >= matrix.length || col >= matrix[0].length)
        return -1;
    //检查单元格是否已经访问过。
    boolean[][] visited = new boolean[matrix.length][matrix[0].length];
    //左右相邻
    int[] lr_neighbour = {0, 0, -1, 1};
    //上下相邻
    int[] tb_neighbour = {1, -1, 0, 0};
    //相同单元格的数量
    int modified = 0;
    //队列
    Queue<Integer> queue = new LinkedList<>();
    queue.add(row);
    queue.add(col);
    //标记当前单元格已访问。
    visited[row][col] = true;
    //当前像素位于(row,col)
    int current_cell = matrix[row][col];
    int x, y;
    while (!queue.isEmpty()){
        row = queue.remove();
        col = queue.remove();
        for (int index = 0;index < 4;index++){
            x = row + tb_neighbour[index];
            y = col + lr_neighbour[index];
            if (x < 0 || y < 0 || x >= matrix.length || y >= matrix[0].length || visited[x][y])
                continue;
            if (current_cell == matrix[x][y]){
                //标记所有其他有效单元格为已访问。
                queue.add(x);
                queue.add(y);
                modified++;
            }
            visited[x][y] = true;
        }
    }
    return modified;
}