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 {
public:
int movingCount(int threshold, int rows, int cols)
{
int count = 0;
if(threshold < 1 || rows < 1 || cols < 1){
return count;
}
bool* visited = new bool[rows*cols];
memset(visited, 0, rows*cols);
count = movingCountCore(threshold, rows, cols, 0, 0, visited);
delete[] visited;
return count;
}
private:
int movingCountCore(int threshold, int rows, int cols, int row, int col, bool* visited){
int count = 0;
if(row >= 0 && row < rows && col >= 0 && col < cols && getDigitSum(row)+getDigitSum(col) <= threshold && !visited[row*cols+col]){
visited[row*cols+col] = true;
count = 1 + movingCountCore(threshold, rows, cols, row+1, col, visited)
+ movingCountCore(threshold, rows, cols, row-1, col, visited)
+ movingCountCore(threshold, rows, cols, row, col+1, visited)
+ movingCountCore(threshold, rows, cols, row, col-1, visited);
}
return count;
}
int getDigitSum(int num){
int sum = 0;
while(num){
sum += num % 10;
num /= 10;
}
return sum;
}
};