@@ -80,11 +80,10 @@ tags:
8080
8181### 方法一:模拟
8282
83- 我们先遍历棋盘,找到车的位置 $(x, y ),ドル然后从 $(x, y )$ 出发,向上下左右四个方向遍历:
83+ 我们先遍历棋盘,找到车的位置 $(i, j ),ドル然后从 $(i, j )$ 出发,向上下左右四个方向遍历:
8484
85- - 如果遇到象或者边界,那么该方向停止遍历;
86- - 如果遇到卒,那么答案加一,然后该方向停止遍历;
87- - 否则,继续遍历。
85+ - 如果不是边界且不是象,则继续向前走;
86+ - 如果是卒,则答案加一,并停止该方向的遍历。
8887
8988遍历完四个方向后,即可得到答案。
9089
@@ -97,50 +96,49 @@ tags:
9796``` python
9897class Solution :
9998 def numRookCaptures (self board : List[List[str ]]) -> int :
100- ans = 0
10199 dirs = (- 1 , 0 , 1 , 0 , - 1 )
102- for i in range (8 ):
103- for j in range (8 ):
100+ n = len (board)
101+ for i in range (n):
102+ for j in range (n):
104103 if board[i][j] == " R"
104+ ans = 0
105105 for a, b in pairwise(dirs):
106- x, y = i, j
107- while 0 <= x + a < 8 and 0 <= y + b < 8 :
108- x, y = x + a, y + b
106+ x, y = i + a, j + b
107+ while 0 <= x < n and 0 <= y < n and board[x][y] != " B"
109108 if board[x][y] == " p"
110109 ans += 1
111110 break
112- if board[x][y] == " B"
113- break
114- return ans
111+ x, y = x + a, y + b
112+ return ans
115113```
116114
117115#### Java
118116
119117``` java
120118class Solution {
121119 public int numRookCaptures (char [][] board ) {
122- int ans = 0 ;
123- int [] dirs = { - 1 , 0 , 1 , 0 , - 1 } ;
124- for (int i = 0 ; i < 8 ; ++ i) {
125- for (int j = 0 ; j < 8 ; ++ j) {
120+ final int [] dirs = { - 1 , 0 , 1 , 0 , - 1 } ;
121+ int n = board . length ;
122+ for (int i = 0 ; i < n ; ++ i) {
123+ for (int j = 0 ; j < n ; ++ j) {
126124 if (board[i][j] == ' R'
125+ int ans = 0 ;
127126 for (int k = 0 ; k < 4 ; ++ k) {
128- int x = i, y = j;
129- int a = dirs[k], b = dirs[k + 1 ];
130- while (x + a >= 0 && x + a < 8 && y + b >= 0 && y + b < 8
131- && board[x + a][y + b] != ' B'
132- x += a;
133- y += b;
127+ int x = i + dirs[k], y = j + dirs[k + 1 ];
128+ while (x >= 0 && x < n && y >= 0 && y < n && board[x][y] != ' B'
134129 if (board[x][y] == ' p'
135130 ++ ans;
136131 break ;
137132 }
133+ x += dirs[k];
134+ y += dirs[k + 1 ];
138135 }
139136 }
137+ return ans;
140138 }
141139 }
142140 }
143- return ans ;
141+ return 0 ;
144142 }
145143}
146144```
@@ -151,27 +149,28 @@ class Solution {
151149class Solution {
152150public:
153151 int numRookCaptures(vector<vector<char >>& board) {
154- int ans = 0 ;
155- int dirs [ 5 ] = {-1, 0, 1, 0, -1} ;
156- for (int i = 0; i < 8 ; ++i) {
157- for (int j = 0; j < 8 ; ++j) {
152+ const int dirs [ 5 ] = {-1, 0, 1, 0, -1} ;
153+ int n = board.size() ;
154+ for (int i = 0; i < n ; ++i) {
155+ for (int j = 0; j < n ; ++j) {
158156 if (board[ i] [ j ] == 'R') {
157+ int ans = 0;
159158 for (int k = 0; k < 4; ++k) {
160- int x = i, y = j;
161- int a = dirs[ k] , b = dirs[ k + 1] ;
162- while (x + a >= 0 && x + a < 8 && y + b >= 0 && y + b < 8 && board[ x + a] [ y + b ] != 'B') {
163- x += a;
164- y += b;
159+ int x = i + dirs[ k] , y = j + dirs[ k + 1] ;
160+ while (x >= 0 && x < n && y >= 0 && y < n && board[ x] [ y ] != 'B') {
165161 if (board[ x] [ y ] == 'p') {
166162 ++ans;
167163 break;
168164 }
165+ x += dirs[ k] ;
166+ y += dirs[ k + 1] ;
169167 }
170168 }
169+ return ans;
171170 }
172171 }
173172 }
174- return ans ;
173+ return 0 ;
175174 }
176175};
177176```
@@ -180,25 +179,93 @@ public:
180179
181180```go
182181func numRookCaptures(board [][]byte) (ans int) {
183- dirs := [5]int{-1, 0, 1, 0, -1}
184- for i := 0; i < 8; i++ {
185- for j := 0; j < 8; j++ {
186- if board[i][j] == 'R' {
187- for k := 0; k < 4; k++ {
188- x, y := i, j
189- a, b := dirs[k], dirs[k+1]
190- for x+a >= 0 && x+a < 8 && y+b >= 0 && y+b < 8 && board[x+a][y+b] != 'B' {
191- x, y = x+a, y+b
192- if board[x][y] == 'p' {
193- ans++
194- break
195- }
196- }
197- }
198- }
199- }
200- }
201- return
182+ dirs := []int{-1, 0, 1, 0, -1}
183+ n := len(board)
184+ for i := 0; i < n; i++ {
185+ for j := 0; j < n; j++ {
186+ if board[i][j] == 'R' {
187+ for k := 0; k < 4; k++ {
188+ x, y := i + dirs[k], j + dirs[k+1]
189+ for x >= 0 && x < n && y >= 0 && y < n && board[x][y] != 'B' {
190+ if board[x][y] == 'p' {
191+ ans++
192+ break
193+ }
194+ x += dirs[k]
195+ y += dirs[k+1]
196+ }
197+ }
198+ return
199+ }
200+ }
201+ }
202+ return
203+ }
204+ ```
205+ 206+ #### TypeScript
207+ 208+ ``` ts
209+ function numRookCaptures(board : string [][]): number {
210+ const = [- 1 , 0 , 1 , 0 , - 1 ];
211+ const = board .length ;
212+ for (let i = 0 ; i < n ; i ++ ) {
213+ for (let j = 0 ; j < n ; j ++ ) {
214+ if (board [i ][j ] === ' R'
215+ let ans = 0 ;
216+ for (let k = 0 ; k < 4 ; k ++ ) {
217+ let [x, y] = [i + dirs [k ], j + dirs [k + 1 ]];
218+ while (x >= 0 && x < n && y >= 0 && y < n && board [x ][y ] !== ' B'
219+ if (board [x ][y ] === ' p'
220+ ans ++ ;
221+ break ;
222+ }
223+ x += dirs [k ];
224+ y += dirs [k + 1 ];
225+ }
226+ }
227+ return ans ;
228+ }
229+ }
230+ }
231+ return 0 ;
232+ }
233+ ```
234+ 235+ #### Rust
236+ 237+ ``` rust
238+ impl Solution {
239+ pub fn num_rook_captures (board : Vec <Vec <char >>) -> i32 {
240+ let dirs = [- 1 , 0 , 1 , 0 , - 1 ];
241+ let n = board . len ();
242+ for i in 0 .. n {
243+ for j in 0 .. n {
244+ if board [i ][j ] == 'R' {
245+ let mut ans = 0 ;
246+ for k in 0 .. 4 {
247+ let mut x = i as i32 + dirs [k ];
248+ let mut y = j as i32 + dirs [k + 1 ];
249+ while x >= 0
250+ && x < n as i32
251+ && y >= 0
252+ && y < n as i32
253+ && board [x as usize ][y as usize ] != 'B'
254+ {
255+ if board [x as usize ][y as usize ] == 'p' {
256+ ans += 1 ;
257+ break ;
258+ }
259+ x += dirs [k ];
260+ y += dirs [k + 1 ];
261+ }
262+ }
263+ return ans ;
264+ }
265+ }
266+ }
267+ 0
268+ }
202269}
203270```
204271
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