劍指Offer-10-機器人運動範圍

/**
 * 機器人的運動範圍：https://leetcode-cn.com/problems/ji-qi-ren-de-yun-dong-fan-wei-lcof/
 * @Description
 */
public class Test11 {
    public int movingCount(int m, int n, int k) {
        if (m <= 0 || n <= 0 || k < 0){
            return 0;
        }
        //訪問數組
        boolean[] isVisited = new boolean[m * n];
        return movingCountCore(m,n,k,0,0,isVisited);
    }

    private int movingCountCore(int m, int n, int k, int row, int col, boolean[] isVisited) {
        if (row < 0 || col < 0 || row >= m || col >= n || isVisited[row * n + col] || getDigitSum(row) + getDigitSum(col) > k){
            return 0;
        }
        isVisited[row * n + col] = true;
        return 1 + movingCountCore(m, n, k, row - 1, col,isVisited) +
                movingCountCore(m, n, k, row , col - 1,isVisited) +
                movingCountCore(m, n, k, row + 1 , col,isVisited) +
                movingCountCore(m, n, k, row , col + 1,isVisited);
    }
    //得到各個數位之和
    private int getDigitSum(int num) {
        int sum = 0;
        while (num > 0){
            sum += num % 10;
            num /= 10;
        }
        return sum;
    }

    public static void main(String[] args) {
        System.out.println(new Test11().movingCount(2, 3, 1));
    }
}