class Solution {

    public int numIslands(char[][] grid) {
        int[] rowMovement = {-1, 0, 1, 0};
        int[] colMovement = {0, -1, 0, 1};
        int numberOfRows = grid.length;
        int numberOfCols = grid[0].length;
        int row;
        int col;
        int movingRow = 0;
        int movingCol = 0;
        int tempRow = 0;
        int tempCol = 0;
        int count = 0;
        char c;
        Queue<Integer> q = new ArrayDeque<Integer>();

        for (row = 0; row < numberOfRows; row++){
            for (col = 0; col < numberOfCols; col++){
                if (grid[row][col] == '1'){ //if it encounters a 1, increment count. Below changes
                    q.add(row);
                    q.add(col);
                    movingRow = row;
                    movingCol = col;
                    while(!q.isEmpty()){
                        movingRow = q.remove();
                        movingCol = q.remove();
                        c = grid[movingRow][movingCol];
                        grid[movingRow][movingCol] = '9';//indicate you've visited now
                        if (c == '1'){
                            for (int k = 0; k < 4; k++){
                                tempRow = movingRow+rowMovement[k];
                                tempCol = movingCol+colMovement[k];
                                if (isValid(tempRow, tempCol, numberOfCols, numberOfRows, grid)){
                                    q.add(tempRow);
                                    q.add(tempCol);
                                }
                            }
                        }
                    }
                    count++;
                }
                if (grid[row][col] == '9'){
                    continue; //move on in for loop if we've already been here;
                }
                else{
                    grid[row][col] = '9'; //set to visited as indicated by 9
                }
            }
        }
        return count;
    }

    public boolean isValid(int row, int col, int numberOfCols, int numberOfRows, char[][] grid){
        if ((row < numberOfRows) && (col < numberOfCols) && (row >= 0) && (col >= 0)){
            return true;
        }
        else{
            return false;
        }
    }
}