题目描述
地上有一个m行n列的方格,从坐标 [0,0] 到坐标 [m-1,n-1] 。一个机器人从坐标 [0, 0] 的格子开始移动,它每次可以向左、右、上、下移动一格(不能移动到方格外),也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?
示例 1:
输入:m = 2, n = 3, k = 1
输出:3
示例 2:
输入:m = 3, n = 1, k = 0
输出:1
提示:
• 1 <= n,m <= 100
• 0 <= k <= 20
解答思路
深度优先搜索即可
疑问:
为什么直接传数组就有问题,传make的数组就没有问题?
提交结果
错误代码
package main
import "fmt"
func main() {
fmt.Println(movingCount(3, 2, 17))
}
func movingCount(m int, n int, k int) int {
var board [100][100]int
return dfs(board, 0, 0, m, n, k)
}
func dfs(board [100][100]int, g, c, m, n, k int) int {
if g < 0 || c < 0 || g >= m || c >= n || g%10+g/10+c%10+c/10 > k || board[g][c] == 1 {
return 0
}
board[g][c] = 1
sum := 1
sum += dfs(board, g-1, c, m, n, k)
sum += dfs(board, g+1, c, m, n, k)
sum += dfs(board, g, c-1, m, n, k)
sum += dfs(board, g, c+1, m, n, k)
return sum
}
func dfs(board [][]byte, g int, c int, word string, n int) bool {
if n == len(word) {
return true
}
if g < 0 || c < 0 || g == len(board) || c == len(board[0]) {
return false
}
if board[g][c] == word[n] {
temp := board[g][c]
board[g][c] = ' '
if dfs(board, g-1, c, word, n+1) ||
dfs(board, g+1, c, word, n+1) ||
dfs(board, g, c-1, word, n+1) ||
dfs(board, g, c+1, word, n+1) {
return true
} else {
board[g][c] = temp
}
}
return false
}
正确代码
package main
import "fmt"
func main() {
fmt.Println(movingCount(3, 2, 17))
}
func movingCount(m int, n int, k int) int {
dp := make([][]int, m+1)
for i := range dp {
dp[i] = make([]int, n+1)
}
return dfs(dp, 0, 0, m, n, k)
}
func dfs(dp [][]int, g, c, m, n, k int) int {
if g < 0 || c < 0 || g >= m || c >= n || g%10+g/10+c%10+c/10 > k || dp[g][c] == 1 {
return 0
}
dp[g][c] = 1
sum := 1
sum += dfs(dp, g-1, c, m, n, k)
sum += dfs(dp, g+1, c, m, n, k)
sum += dfs(dp, g, c-1, m, n, k)
sum += dfs(dp, g, c+1, m, n, k)
return sum
}
来源:力扣(LeetCode)
链接:https://leetcode-cn.com/problems/ji-qi-ren-de-yun-dong-fan-wei-lcof
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