[Swift]LeetCode999.车的可用捕获量|AvailableCapturesforRook

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› 移动开发›Swift 教程

原作者: [db:作者] 来自: [db:来源] 收藏邀请

★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★
➤微信公众号：山青咏芝（shanqingyongzhi）
➤博客园地址：山青咏芝（https://www.cnblogs.com/strengthen/）
➤GitHub地址：https://github.com/strengthen/LeetCode
➤原文地址：https://www.cnblogs.com/strengthen/p/10429051.html
➤如果链接不是山青咏芝的博客园地址，则可能是爬取作者的文章。
➤原文已修改更新！强烈建议点击原文地址阅读！支持作者！支持原创！
★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★

热烈欢迎，请直接点击！！！

进入博主App Store主页，下载使用各个作品！！！

注：博主将坚持每月上线一个新app！！！

On an 8 x 8 chessboard, there is one white rook. There also may be empty squares, white bishops, and black pawns. These are given as characters 'R', '.', 'B', and 'p' respectively. Uppercase characters represent white pieces, and lowercase characters represent black pieces.

The rook moves as in the rules of Chess: it chooses one of four cardinal directions (north, east, west, and south), then moves in that direction until it chooses to stop, reaches the edge of the board, or captures an opposite colored pawn by moving to the same square it occupies. Also, rooks cannot move into the same square as other friendly bishops.

Return the number of pawns the rook can capture in one move.

Example 1:

Input: 3
Explanation: 
In this example the rook is able to capture all the pawns.

Example 2:

Input: 0
Explanation: 
Bishops are blocking the rook to capture any pawn.

Example 3:

Input: 3
Explanation: 
The rook can capture the pawns at positions b5, d6 and f5.

Note:

board.length == board[i].length == 8
board[i][j] is either 'R', '.', 'B', or 'p'
There is exactly one cell with board[i][j] == 'R'

在一个 8 x 8 的棋盘上，有一个白色车（rook）。也可能有空方块，白色的象（bishop）和黑色的卒（pawn）。它们分别以字符 “R”，“.”，“B” 和 “p” 给出。大写字符表示白棋，小写字符表示黑棋。

车按国际象棋中的规则移动：它选择四个基本方向中的一个（北，东，西和南），然后朝那个方向移动，直到它选择停止、到达棋盘的边缘或移动到同一方格来捕获该方格上颜色相反的卒。另外，车不能与其他友方（白色）象进入同一个方格。

返回车能够在一次移动中捕获到的卒的数量。

示例 1：

输入：[[".",".",".",".",".",".",".","."],[".",".",".","p",".",".",".","."],[".",".",".","R",".",".",".","p"],[".",".",".",".",".",".",".","."],[".",".",".",".",".",".",".","."],[".",".",".","p",".",".",".","."],[".",".",".",".",".",".",".","."],[".",".",".",".",".",".",".","."]]
输出：3
解释：
在本例中，车能够捕获所有的卒。

示例 2：

输入：[[".",".",".",".",".",".",".","."],[".","p","p","p","p","p",".","."],[".","p","p","B","p","p",".","."],[".","p","B","R","B","p",".","."],[".","p","p","B","p","p",".","."],[".","p","p","p","p","p",".","."],[".",".",".",".",".",".",".","."],[".",".",".",".",".",".",".","."]]
输出：0
解释：
象阻止了车捕获任何卒。

示例 3：

输入：[[".",".",".",".",".",".",".","."],[".",".",".","p",".",".",".","."],[".",".",".","p",".",".",".","."],["p","p",".","R",".","p","B","."],[".",".",".",".",".",".",".","."],[".",".",".","B",".",".",".","."],[".",".",".","p",".",".",".","."],[".",".",".",".",".",".",".","."]]
输出：3
解释： 
车可以捕获位置 b5，d6 和 f5 的卒。

提示：

board.length == board[i].length == 8
board[i][j] 可以是 'R'，'.'，'B' 或 'p'
只有一个格子上存在 board[i][j] == 'R'

8ms

 1 class Solution {
 2     func numRookCaptures(_ board: [[Character]]) -> Int {
 3         var rii : Int?
 4         var rjj : Int?
 5         
 6         for i in 0...63 {
 7             if board[i%8][i/8] == "R" {
 8                 rii = i%8
 9                 rjj = i / 8
10                 break
11             }
12         }
13         guard var ri = rii, var rj = rjj else {
14             return 0
15         }
16         
17         var result = 0
18         var i = ri-1
19         while i >= 0 {
20             if board[i][rj] == "B" {
21                 break
22             }
23             if board[i][rj] == "p" {
24                 result += 1
25                 break
26             }
27             i -= 1
28         }
29         i = ri + 1
30         while i < 8 {
31              if board[i][rj] == "B" {
32                 break
33             }
34             if board[i][rj] == "p" {
35                 result += 1
36                 break
37             }
38             i += 1
39         }
40         
41         i = rj-1
42         while i >= 0 {
43             if board[ri][i] == "B" {
44                 break
45             }
46             if board[ri][i] == "p" {
47                 result += 1
48                 break
49             }
50             i -= 1
51         }
52         i = rj + 1
53         while i < 8 {
54              if board[ri][i] == "B" {
55                 break
56             }
57             if board[ri][i] == "p" {
58                 result += 1
59                 break
60             }
61             i += 1
62         }
63         return result
64     }
65 }

Runtime: 12 ms

Memory Usage: 19.8 MB

 1 class Solution {
 2     func numRookCaptures(_ board: [[Character]]) -> Int {
 3         var cnt:Int = 0
 4         var n:Int = board.count
 5         var m:Int = board[0].count
 6         var x:Int = 0
 7         var y:Int = 0
 8         for i in 0..<n
 9         {
10             for j in 0..<m
11             {
12                 if board[i][j] == "R"
13                 {
14                     x = i
15                     y = j
16                     break
17                 }
18             }
19         }
20         for i in stride(from:x - 1,through:0,by:-1)
21         {
22             if board[i][y] == "p"
23             {
24                 cnt += 1
25                 break
26             }
27             else if board[i][y] != "."
28             {
29                 break
30             }
31         }
32         for i in (x + 1)..<n
33         {
34             if board[i][y] == "p"
35             {
36                 cnt += 1
37                 break
38             }
39             else if board[i][y] != "."
40             {
41                 break
42             }            
43         }
44         for j in stride(from:y - 1,through:0,by:-1)
45         {
46             if board[x][j] == "p"
47             {
48                 cnt += 1
49                 break
50             }
51             else if board[x][j] != "."
52             {
53                  break
54             }
55         }
56         for j in (y + 1)..<m
57         {
58             if board[x][j] == "p"
59             {
60                 cnt += 1
61                 break
62             }
63             else if board[x][j] != "."
64             {
65                 break
66             }
67         }
68         return cnt        
69     }
70 }

12ms

 1 class Solution {
 2     func numRookCaptures(_ board: [[Character]]) -> Int {
 3         // store the number of black pawns the Rook can catch
 4         var capturablePawns = 0
 5 
 6         // determine where the rook (R) is
 7         var rookSpace = (row: 0, column: 0)
 8         for row in board {
 9             if row.contains("R") {
10                 rookSpace.row = board.index(of: row) ?? 0
11                 for column in row {
12                     if column == "R" {
13                         rookSpace.column = row.index(of: column) ?? 0
14                     }
15                 }
16             }
17         }
18 
19         var R = false
20         var p = false
21 
22         for col in board[rookSpace.row] {
23             if col == "R" {
24                 R = true
25             } else if col == "p" {
26                 p = true
27             } else if col == "B" && (R || p) {
28                 R = false
29                 p = false
30             }
31 
32             if R && p {
33                 capturablePawns += 1
34                 if col == "R" {
35                     p = false
36                 } else if col == "p" {
37                     R = false
38                 }
39             }
40         }
41 
42         R = false
43         p = false
44 
45         for row in board {
46             if row[rookSpace.column] == "R" {
47                 R = true
48             } else if row[rookSpace.column] == "p" {
49                 p = true
50             } else if row[rookSpace.column] == "B" && (R || p) {
51                 R = false
52                 p = false
53             }
54 
55             if R && p {
56                 capturablePawns += 1
57                 if row[rookSpace.column] == "R" {
58                     p = false
59                 } else if row[rookSpace.column] == "p" {
60                     R = false
61                 }
62             }
63         }
64 
65         // return the number of pawns
66         return capturablePawns
67     }
68 }

16ms

  1 class Solution {
  2     func numRookCaptures(_ board: [[Character]]) -> Int {
  3         var rookPosition: (row: Int, column: Int) = (-1, -1)
  4         var soliderPositions: [(row: Int, column: Int)]
  5         
  6         for (rowIndex, row) in board.enumerated(){
  7             for (columnIndex, chess) in row.enumerated(){
  8                 if chess == "R"{
  9                     rookPosition.row = rowIndex
 10                     rookPosition.column = columnIndex
 11                 }
 12             }
 13         }
 14         let up = checkUpper(board: board, rookPosition: rookPosition)
 15         let low = checkLower(board: board, rookPosition: rookPosition)
 16         let left = checkLeft(board: board, rookPosition: rookPosition)
 17         let right = checkRight(board: board, rookPosition: rookPosition)
 18 
 19         return up + low + left + right
 20     }
 21     
 22     func checkUpper(board: [[Character]], rookPosition: (row: Int, column: Int))-> Int{
 23         var count = 0
 24 
 25         if rookPosition.row >= 0 && rookPosition.column >= 0{
 26             var row = rookPosition.row - 1
 27             while row >= 0{
 28                 if board[row][rookPosition.column] == "."{
 29                     row -= 1
 30                 }else if board[row][rookPosition.column] == "p"{
 31                     count += 1
 32                     break
 33                 }else{
 34                     break
 35                 }
 36             }
 37             print(count)
 38         }
 39         return count
 40     }
 41     
 42     func checkLower(board: [[Character]], rookPosition: (row: Int, column: Int)) -> Int{
 43         var count = 0
 44 
 45         if rookPosition.row >= 0 && rookPosition.column >= 0{
 46             var row = rookPosition.row + 1
 47             while row < board.count{
 48                 if board[row][rookPosition.column] == "."{
 49                     row += 1
 50                 }else if board[row][rookPosition.column] == "p"{
 51                     count += 1
 52                     break
 53                 }else{
 54                     break
 55                 }
 56             }
 57             print(count)
 58         }
 59         return count
 60     }
 61     
 62     func checkLeft(board: [[Character]], rookPosition: (row: Int, column: Int))-> Int{
 63         var count = 0
 64         if rookPosition.row >= 0 && rookPosition.column >= 0{
 65             var column = rookPosition.column - 1
 66             
 67             while column > 0{
 68                 if board[rookPosition.row][column] == "."{
 69                     column -= 1
 70                 }else if board[rookPosition.row][column] == "p"{
 71                     count += 1
 72                     break
 73                 }else{
 74                     break
 75                 }
 76             }
 77             print(count)
 78         }
 79         return count
 80     }
 81     func checkRight(board: [[Character]], rookPosition: (row: Int, column: Int))-> Int{
 82         var count = 0
 83 
 84         if rookPosition.row >= 0 && rookPosition.column >= 0{
 85             var column = rookPosition.column + 1
 86             while column < board.count{
 87                 if board[rookPosition.row][column] == "."{
 88                     column += 1
 89                 }else if board[rookPosition.row][column] == "p"{
 90                     count += 1
 91                     break
 92                 }else{
 93                     break
 94                 }
 95             }
 96             print(count)
 97         }
 98         return count
 99     }
100 }