Available catches [simple] 999. car

link

Title Description

Thinking

First find 车the location.
Then 上下左右four directions Search:

• If met 象, end search
• If met 卒, num++end search
• If you are out of bounds to end the search

1. Code

class Solution {
    public int numRookCaptures(char[][] board) {
        //找到'R'的位置board[row][col]
        int row = 0;
        int col = 0;
        for(int i = 0; i < board.length ;i++){
            for(int j = 0; j < board[0].length ;j++){
                if(board[i][j] == 'R'){
                    row = i;
                    col = j;
                }
            }
        }
        int num = 0;
        
        int i = row;
        int j = col;
        while(j < board.length){
            if(board[i][j] == 'p'){
                num++;
                break;
            }
            if(board[i][j] == 'B'){
                break;
            }
            j++;
        }
        
        i = row;
        j = col;
        while(j >= 0){
            if(board[i][j] == 'p'){
                num++;
                break;
            }
            if(board[i][j] == 'B'){
                break;
            }
            j--;
        }
        
        i = row;
        j = col;
        while(i >= 0){
            if(board[i][j] == 'p'){
                num++;
                break;
            }
            if(board[i][j] == 'B'){
                break;
            }
            i--;
        }
        
        i = row;
        j = col;
        while(i < board.length){
            if(board[i][j] == 'p'){
                num++;
                break;
            }
            if(board[i][j] == 'B'){
                break;
            }
            i++;
        }
        
        return num;
    }
}

2. The complexity analysis

Time complexity: O(N^2)
space complexity:O(1)