剑指offer13 机器人的运动范围

 

public class Solution {
    public int movingCount(int threshold, int rows, int cols)
    {
        if(rows<1||cols<1||threshold<0) return 0;
        
        boolean[][] reached = new boolean[rows][cols];
        int[] count = new int[1];count[0]=0;
        getCount(threshold,rows,cols,0,0,reached,count);
        return count[0];
        
    }
    private void getCount(int threshold,int rows,int cols,int row,int col,boolean[][] reached,int[] count){
        if(!isReachable(threshold,rows,cols,row,col)||reached[row][col]) return;
        
        reached[row][col]=true;
        count[0]=count[0]+1;
        getCount(threshold,rows,cols,row+1,col,reached,count);
        getCount(threshold,rows,cols,row-1,col,reached,count);
        getCount(threshold,rows,cols,row,col+1,reached,count);
        getCount(threshold,rows,cols,row,col-1,reached,count);
    }
    private boolean isReachable(int threshold,int rows,int cols,int row,int col){
        if(row<0||row>=rows||col<0||col>=cols) return false;
        int sum = getSum(col)+getSum(row);
        if(sum>threshold) return false;
        return true;
    }
    private int getSum(int num){
        int sum = 0;
        while(num!=0){
            sum+=num%10;
            num/=10;
        }
        return sum;
    }
}

运行时间：14ms

占用内存：9416k

 

# -*- coding:utf-8 -*-
class Solution:
    def movingCount(self, threshold, rows, cols):
        # write code here
        if threshold < 0 or rows<1 or cols<1:
            return 0
        
        count = [0,]
        reached = [[False for i in range(cols)] for j in range(rows)]
        self.getCount(threshold,rows,cols,0,0,count,reached)
        return count[0]
    
    def getCount(self,threshold,rows,cols,row,col,count,reached):
        if row<0 or col<0 or row>=rows or col>=cols or reached[row][col]:
            return
        if self.digitcount(row)+self.digitcount(col)> threshold:
            return
        reached[row][col] = True
        count[0]+=1
        self.getCount(threshold,rows,cols,row+1,col,count,reached)
        self.getCount(threshold,rows,cols,row-1,col,count,reached)
        self.getCount(threshold,rows,cols,row,col+1,count,reached)
        self.getCount(threshold,rows,cols,row,col-1,count,reached)
        
    def digitcount(self,num):
        ans = 0 
        while num>0:
            ans += num%10
            num /= 10
        return ans

运行时间：24ms

占用内存：5724k