/*******************************************************************
*《剑指Offer——名企面试官精讲典型编程题》C++代码
*
* htfeng
* 2018.09.27
*
* 面试题13: 机器人的运动范围
* 题目:地上有一个m行n列的方格。一个机器人从坐标(0, 0)的格子开始移动,它
* 每一次可以向左、右、上、下移动一格,但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。
* 但它不能进入方格(35, 38),因为3+5+3+8=19。请问该机器人能够到达多少个格子?
*******************************************************************/
class Solution {
public:
int getDigitSum(int number);
bool check(int threshold, int rows, int cols, int row, int col, bool* visited);
int movingCountCore(int threshold, int rows, int cols, int row, int col, bool* visited);
int movingCount(int threshold, int rows, int cols) {
if (threshold < 0 || rows <= 0 || cols <= 0) {
return 0;
}
bool *visited = new bool[rows * cols];
for (int i = 0; i < rows * cols; i++)
visited[i] = false;
int count = movingCountCore(threshold, rows, cols, 0, 0, visited);
delete[] visited;
return count;
}
int movingCountCore(int threshold, int rows, int cols, int row, int col, bool* visited) {
int count = 0;
if (check(threshold, rows, cols, row, col, visited)) {
visited[row * cols + col] = true;
count = 1 + movingCountCore(threshold, rows, cols, row - 1, col, visited)
+ movingCountCore(threshold, rows, cols, row, col - 1, visited)
+ movingCountCore(threshold, rows, cols, row + 1, col, visited)
+ movingCountCore(threshold, rows, cols, row, col + 1, visited);
}
return count;
}
bool check(int threshold, int rows, int cols, int row, int col, bool* visited) {
if (row >= 0 && col >= 0 && row < rows && col < cols
&& getDigitSum(row) + getDigitSum(col) <= threshold
&& !visited[row * cols + col])
return true;
return false;
}
int getDigitSum(int number) {
int sum = 0;
while (number > 0) {
sum += number % 10;
number = number / 10;
}
return sum;
}
};
博客园上的格式还没有修改好[原文来自博主CSDN]。