剑指offer66:机器人的活动范围

地上有一个m行和n列的方格。一个机器人从坐标0,0的格子开始移动,每一次只能向左,右,上,下四个方向移动一格,但是不能进入行坐标和列坐标的数位之和大于k的格子。 例如,当k为18时,机器人能够进入方格(35,37),因为3+5+3+7 = 18。但是,它不能进入方格(35,38),因为3+5+3+8 = 19。请问该机器人能够达到多少个格子?

class Solution {
private:
    int sumOfNumber(int x){
        int sum = 0;
        while(x){
            sum += x % 10;
            x = x / 10;
        }
        return sum;
    }
    int movingCountDFSHelper(int threshold, int rows, int cols, int r, int c,
            vector<vector<bool>>& visited) {
        if (r < 0 || r >= rows || c < 0 || c >= cols || visited[r][c]
                || threshold < sumOfNumber(r) + sumOfNumber(c)) {
            return 0;
        }
        visited[r][c] = true;
        return 1+ movingCountDFSHelper(threshold, rows, cols, r + 1, c, visited)
                + movingCountDFSHelper(threshold, rows, cols, r - 1, c, visited)
                + movingCountDFSHelper(threshold, rows, cols, r, c - 1, visited)
                + movingCountDFSHelper(threshold, rows, cols, r, c + 1, visited);
    }
public:
    int movingCount(int threshold, int rows, int cols) {
        if (rows <= 0 || cols <= 0)
            return 0;
        vector<vector<bool>> visited(rows, vector<bool>(cols, false));
        return movingCountDFSHelper(threshold, rows, cols, 0, 0, visited);

    }
};

 

posted @ 2017-04-26 10:00  wxquare  阅读(279)  评论(0编辑  收藏  举报