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feat: update solutions to lc problem: No.0999
No.0999.Available Captures for Rook
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‎solution/0900-0999/0999.Available Captures for Rook/README.md

+74-86
Original file line numberDiff line numberDiff line change
@@ -65,7 +65,17 @@
6565

6666
<!-- 这里可写通用的实现逻辑 -->
6767

68-
先找到 R 的位置，之后向“上、下、左、右”四个方向查找，累加结果。
68+
**方法一：模拟**
69+
70+
我们先遍历棋盘，找到车的位置 $(x, y)$，然后从 $(x, y)$ 出发，向上下左右四个方向遍历：
71+
72+
- 如果遇到象或者边界，那么该方向停止遍历；
73+
- 如果遇到卒，那么答案加一，然后该方向停止遍历；
74+
- 否则，继续遍历。
75+
76+
遍历完四个方向后，即可得到答案。
77+
78+
时间复杂度 $O(m \times n)$，其中 $m$ 和 $n$ 分别是棋盘的行数和列数，本题中 $m = n = 8$。空间复杂度 $O(1)$。
6979

7080
<!-- tabs:start -->
7181

@@ -76,20 +86,20 @@
7686
```python
7787
class Solution:
7888
def numRookCaptures(self, board: List[List[str]]) -> int:
79-
x, y, n = 0, 0, 8
80-
for i in range(n):
81-
for j in range(n):
82-
if board[i][j] == 'R':
83-
x, y = i, j
84-
break
8589
ans = 0
86-
for a, b in [[0, -1], [0, 1], [-1, 0], [1, 0]]:
87-
i, j = x, y
88-
while 0 <= i + a < n and 0 <= j + b < n and board[i + a][j + b] != 'B':
89-
i, j = i + a, j + b
90-
if board[i][j] == 'p':
91-
ans += 1
92-
break
90+
dirs = (-1, 0, 1, 0, -1)
91+
for i in range(8):
92+
for j in range(8):
93+
if board[i][j] == "R":
94+
for a, b in pairwise(dirs):
95+
x, y = i, j
96+
while 0 <= x + a < 8 and 0 <= y + b < 8:
97+
x, y = x + a, y + b
98+
if board[x][y] == "p":
99+
ans += 1
100+
break
101+
if board[x][y] == "B":
102+
break
93103
return ans
94104
```
95105

@@ -100,34 +110,27 @@ class Solution:
100110
```java
101111
class Solution {
102112
public int numRookCaptures(char[][] board) {
103-
int[] pos = find(board);
104-
int ans = 0, n = 8;
105-
int[][] dirs = new int[][] {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
106-
for (int[] dir : dirs) {
107-
int x = pos[0], y = pos[1], a = dir[0], b = dir[1];
108-
while (
109-
x + a >= 0 && x + a < n && y + b >= 0 && y + b < n && board[x + a][y + b] != 'B') {
110-
x += a;
111-
y += b;
112-
if (board[x][y] == 'p') {
113-
++ans;
114-
break;
115-
}
116-
}
117-
}
118-
return ans;
119-
}
120-
121-
private int[] find(char[][] board) {
122-
int n = 8;
123-
for (int i = 0; i < n; ++i) {
124-
for (int j = 0; j < n; ++j) {
113+
int ans = 0;
114+
int[] dirs = {-1, 0, 1, 0, -1};
115+
for (int i = 0; i < 8; ++i) {
116+
for (int j = 0; j < 8; ++j) {
125117
if (board[i][j] == 'R') {
126-
return new int[] {i, j};
118+
for (int k = 0; k < 4; ++k) {
119+
int x = i, y = j;
120+
int a = dirs[k], b = dirs[k + 1];
121+
while (x + a >= 0 && x + a < 8 && y + b >= 0 && y + b < 8 && board[x + a][y + b] != 'B') {
122+
x += a;
123+
y += b;
124+
if (board[x][y] == 'p') {
125+
++ans;
126+
break;
127+
}
128+
}
129+
}
127130
}
128131
}
129132
}
130-
return null;
133+
return ans;
131134
}
132135
}
133136
```
@@ -138,69 +141,54 @@ class Solution {
138141
class Solution {
139142
public:
140143
int numRookCaptures(vector<vector<char>>& board) {
141-
vector<int> pos = find(board);
142-
int ans = 0, n = 8;
143-
vector<vector<int>> dirs = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
144-
for (auto& dir : dirs) {
145-
int x = pos[0], y = pos[1], a = dir[0], b = dir[1];
146-
while (x + a >= 0 && x + a < n && y + b >= 0 && y + b < n && board[x + a][y + b] != 'B') {
147-
x += a;
148-
y += b;
149-
if (board[x][y] == 'p') {
150-
++ans;
151-
break;
152-
}
153-
}
154-
}
155-
return ans;
156-
}
157-
158-
vector<int> find(vector<vector<char>>& board) {
159-
int n = 8;
160-
for (int i = 0; i < n; ++i) {
161-
for (int j = 0; j < n; ++j) {
144+
int ans = 0;
145+
int dirs[5] = {-1, 0, 1, 0, -1};
146+
for (int i = 0; i < 8; ++i) {
147+
for (int j = 0; j < 8; ++j) {
162148
if (board[i][j] == 'R') {
163-
return {i, j};
149+
for (int k = 0; k < 4; ++k) {
150+
int x = i, y = j;
151+
int a = dirs[k], b = dirs[k + 1];
152+
while (x + a >= 0 && x + a < 8 && y + b >= 0 && y + b < 8 && board[x + a][y + b] != 'B') {
153+
x += a;
154+
y += b;
155+
if (board[x][y] == 'p') {
156+
++ans;
157+
break;
158+
}
159+
}
160+
}
164161
}
165162
}
166163
}
167-
return {};
164+
return ans;
168165
}
169166
};
170167
```
171168
172169
### **Go**
173170
174171
```go
175-
func numRookCaptures(board [][]byte) int {
176-
n := 8
177-
178-
find := func() []int {
179-
for i := 0; i < n; i++ {
180-
for j := 0; j < n; j++ {
181-
if board[i][j] == 'R' {
182-
return []int{i, j}
172+
func numRookCaptures(board [][]byte) (ans int) {
173+
dirs := [5]int{-1, 0, 1, 0, -1}
174+
for i := 0; i < 8; i++ {
175+
for j := 0; j < 8; j++ {
176+
if board[i][j] == 'R' {
177+
for k := 0; k < 4; k++ {
178+
x, y := i, j
179+
a, b := dirs[k], dirs[k+1]
180+
for x+a >= 0 && x+a < 8 && y+b >= 0 && y+b < 8 && board[x+a][y+b] != 'B' {
181+
x, y = x+a, y+b
182+
if board[x][y] == 'p' {
183+
ans++
184+
break
185+
}
186+
}
183187
}
184188
}
185189
}
186-
return []int{}
187-
}
188-
189-
pos := find()
190-
ans := 0
191-
dirs := [4][2]int{{0, -1}, {0, 1}, {1, 0}, {-1, 0}}
192-
for _, dir := range dirs {
193-
x, y, a, b := pos[0], pos[1], dir[0], dir[1]
194-
for x+a >= 0 && x+a < n && y+b >= 0 && y+b < n && board[x+a][y+b] != 'B' {
195-
x += a
196-
y += b
197-
if board[x][y] == 'p' {
198-
ans++
199-
break
200-
}
201-
}
202190
}
203-
return ans
191+
return
204192
}
205193
```
206194

‎solution/0900-0999/0999.Available Captures for Rook/README_EN.md

+63-85
Original file line numberDiff line numberDiff line change
@@ -54,20 +54,20 @@
5454
```python
5555
class Solution:
5656
def numRookCaptures(self, board: List[List[str]]) -> int:
57-
x, y, n = 0, 0, 8
58-
for i in range(n):
59-
for j in range(n):
60-
if board[i][j] == 'R':
61-
x, y = i, j
62-
break
6357
ans = 0
64-
for a, b in [[0, -1], [0, 1], [-1, 0], [1, 0]]:
65-
i, j = x, y
66-
while 0 <= i + a < n and 0 <= j + b < n and board[i + a][j + b] != 'B':
67-
i, j = i + a, j + b
68-
if board[i][j] == 'p':
69-
ans += 1
70-
break
58+
dirs = (-1, 0, 1, 0, -1)
59+
for i in range(8):
60+
for j in range(8):
61+
if board[i][j] == "R":
62+
for a, b in pairwise(dirs):
63+
x, y = i, j
64+
while 0 <= x + a < 8 and 0 <= y + b < 8:
65+
x, y = x + a, y + b
66+
if board[x][y] == "p":
67+
ans += 1
68+
break
69+
if board[x][y] == "B":
70+
break
7171
return ans
7272
```
7373

@@ -76,34 +76,27 @@ class Solution:
7676
```java
7777
class Solution {
7878
public int numRookCaptures(char[][] board) {
79-
int[] pos = find(board);
80-
int ans = 0, n = 8;
81-
int[][] dirs = new int[][] {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
82-
for (int[] dir : dirs) {
83-
int x = pos[0], y = pos[1], a = dir[0], b = dir[1];
84-
while (
85-
x + a >= 0 && x + a < n && y + b >= 0 && y + b < n && board[x + a][y + b] != 'B') {
86-
x += a;
87-
y += b;
88-
if (board[x][y] == 'p') {
89-
++ans;
90-
break;
91-
}
92-
}
93-
}
94-
return ans;
95-
}
96-
97-
private int[] find(char[][] board) {
98-
int n = 8;
99-
for (int i = 0; i < n; ++i) {
100-
for (int j = 0; j < n; ++j) {
79+
int ans = 0;
80+
int[] dirs = {-1, 0, 1, 0, -1};
81+
for (int i = 0; i < 8; ++i) {
82+
for (int j = 0; j < 8; ++j) {
10183
if (board[i][j] == 'R') {
102-
return new int[] {i, j};
84+
for (int k = 0; k < 4; ++k) {
85+
int x = i, y = j;
86+
int a = dirs[k], b = dirs[k + 1];
87+
while (x + a >= 0 && x + a < 8 && y + b >= 0 && y + b < 8 && board[x + a][y + b] != 'B') {
88+
x += a;
89+
y += b;
90+
if (board[x][y] == 'p') {
91+
++ans;
92+
break;
93+
}
94+
}
95+
}
10396
}
10497
}
10598
}
106-
return null;
99+
return ans;
107100
}
108101
}
109102
```
@@ -114,69 +107,54 @@ class Solution {
114107
class Solution {
115108
public:
116109
int numRookCaptures(vector<vector<char>>& board) {
117-
vector<int> pos = find(board);
118-
int ans = 0, n = 8;
119-
vector<vector<int>> dirs = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
120-
for (auto& dir : dirs) {
121-
int x = pos[0], y = pos[1], a = dir[0], b = dir[1];
122-
while (x + a >= 0 && x + a < n && y + b >= 0 && y + b < n && board[x + a][y + b] != 'B') {
123-
x += a;
124-
y += b;
125-
if (board[x][y] == 'p') {
126-
++ans;
127-
break;
128-
}
129-
}
130-
}
131-
return ans;
132-
}
133-
134-
vector<int> find(vector<vector<char>>& board) {
135-
int n = 8;
136-
for (int i = 0; i < n; ++i) {
137-
for (int j = 0; j < n; ++j) {
110+
int ans = 0;
111+
int dirs[5] = {-1, 0, 1, 0, -1};
112+
for (int i = 0; i < 8; ++i) {
113+
for (int j = 0; j < 8; ++j) {
138114
if (board[i][j] == 'R') {
139-
return {i, j};
115+
for (int k = 0; k < 4; ++k) {
116+
int x = i, y = j;
117+
int a = dirs[k], b = dirs[k + 1];
118+
while (x + a >= 0 && x + a < 8 && y + b >= 0 && y + b < 8 && board[x + a][y + b] != 'B') {
119+
x += a;
120+
y += b;
121+
if (board[x][y] == 'p') {
122+
++ans;
123+
break;
124+
}
125+
}
126+
}
140127
}
141128
}
142129
}
143-
return {};
130+
return ans;
144131
}
145132
};
146133
```
147134
148135
### **Go**
149136
150137
```go
151-
func numRookCaptures(board [][]byte) int {
152-
n := 8
153-
154-
find := func() []int {
155-
for i := 0; i < n; i++ {
156-
for j := 0; j < n; j++ {
157-
if board[i][j] == 'R' {
158-
return []int{i, j}
138+
func numRookCaptures(board [][]byte) (ans int) {
139+
dirs := [5]int{-1, 0, 1, 0, -1}
140+
for i := 0; i < 8; i++ {
141+
for j := 0; j < 8; j++ {
142+
if board[i][j] == 'R' {
143+
for k := 0; k < 4; k++ {
144+
x, y := i, j
145+
a, b := dirs[k], dirs[k+1]
146+
for x+a >= 0 && x+a < 8 && y+b >= 0 && y+b < 8 && board[x+a][y+b] != 'B' {
147+
x, y = x+a, y+b
148+
if board[x][y] == 'p' {
149+
ans++
150+
break
151+
}
152+
}
159153
}
160154
}
161155
}
162-
return []int{}
163-
}
164-
165-
pos := find()
166-
ans := 0
167-
dirs := [4][2]int{{0, -1}, {0, 1}, {1, 0}, {-1, 0}}
168-
for _, dir := range dirs {
169-
x, y, a, b := pos[0], pos[1], dir[0], dir[1]
170-
for x+a >= 0 && x+a < n && y+b >= 0 && y+b < n && board[x+a][y+b] != 'B' {
171-
x += a
172-
y += b
173-
if board[x][y] == 'p' {
174-
ans++
175-
break
176-
}
177-
}
178156
}
179-
return ans
157+
return
180158
}
181159
```
182160

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