leetcode 第576题-出界的路径数

链接：https://leetcode-cn.com/problems/out-of-boundary-paths

package leetcode

func FindPaths(m int, n int, maxMove int, startRow int, startColumn int) int {
    mod := 1000000007
    flag := make([][][]int, m, m)
    for i := 0; i < m; i++ {
        flag[i] = make([][]int, n, n)
        for j := 0; j < n; j++ {
            flag[i][j] = make([]int, maxMove+1, maxMove+1)
            for t := 1; t <= maxMove; t++ {
                flag[i][j][t] = -1
            }
        }
    }

    var deep func(move, x, y int) int
    deep = func(move, x, y int) int {
        count := flag[x][y][move]
        if count != -1 {
            return count
        }
        count = 0

        if move == 1 {
            if x-1 < 0 {
                count++
            }
            if x+1 >= m {
                count++
            }
            if y-1 < 0 {
                count++
            }
            if y+1 >= n {
                count++
            }
            flag[x][y][move] = count % mod //存储
            return count
        }

        if x-1 >= 0 {
            count += deep(move-1, x-1, y)
        }
        if x+1 < m {
            count += deep(move-1, x+1, y)
        }
        if y-1 >= 0 {
            count += deep(move-1, x, y-1)
        }
        if y+1 < n {
            count += deep(move-1, x, y+1)
        }
        flag[x][y][move] = count % mod //存储
        return count % mod
    }

    var sum int
    for i := 1; i <= maxMove; i++ {
        sum += deep(i, startRow, startColumn)
    }

    return sum % mod
}