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feat: add solutions to lc problem: No.0838
No.0838.Push Dominoes
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‎solution/0800-0899/0838.Push Dominoes/README.md

Lines changed: 163 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -46,22 +46,184 @@
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<!-- 这里可写通用的实现逻辑 -->
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BFS。设 time 记录骨牌翻倒或者确定不翻倒的时间，翻倒的骨牌不会对正在翻倒或者已经翻倒的骨牌施加力，force 记录骨牌受到的力，骨牌仅在受到单侧的力时会翻倒。
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初始时，将所有受力点 i (`dominoes[i] != '.'`)入队，并设置 `time[i] = 0`。
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<!-- tabs:start -->
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### **Python3**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
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class Solution:
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def pushDominoes(self, dominoes: str) -> str:
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n = len(dominoes)
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q = deque()
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time = [-1] * n
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force = defaultdict(list)
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for i, f in enumerate(dominoes):
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if f != '.':
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q.append(i)
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time[i] = 0
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force[i].append(f)
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ans = ['.'] * n
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while q:
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i = q.popleft()
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if len(force[i]) == 1:
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ans[i] = f = force[i][0]
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j = i - 1 if f == 'L' else i + 1
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if 0 <= j < n:
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t = time[i]
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if time[j] == -1:
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q.append(j)
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time[j] = t + 1
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force[j].append(f)
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elif time[j] == t + 1:
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force[j].append(f)
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return ''.join(ans)
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```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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class Solution {
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public String pushDominoes(String dominoes) {
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int n = dominoes.length();
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Deque<Integer> q = new ArrayDeque<>();
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int[] time = new int[n];
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Arrays.fill(time, -1);
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List<Character>[] force = new List[n];
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for (int i = 0; i < n; ++i) {
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force[i] = new ArrayList<>();
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}
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for (int i = 0; i < n; ++i) {
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char f = dominoes.charAt(i);
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if (f != '.') {
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q.offer(i);
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time[i] = 0;
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force[i].add(f);
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}
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}
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char[] ans = new char[n];
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Arrays.fill(ans, '.');
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while (!q.isEmpty()) {
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int i = q.poll();
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if (force[i].size() == 1) {
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ans[i] = force[i].get(0);
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char f = ans[i];
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int j = f == 'L' ? i - 1 : i + 1;
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if (j >= 0 && j < n) {
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int t = time[i];
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if (time[j] == -1) {
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q.offer(j);
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time[j] = t + 1;
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force[j].add(f);
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} else if (time[j] == t + 1) {
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force[j].add(f);
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}
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}
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}
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}
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return new String(ans);
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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string pushDominoes(string dominoes) {
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int n = dominoes.size();
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queue<int> q;
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vector<int> time(n, - 1);
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vector<string> force(n);
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for (int i = 0; i < n; i++)
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{
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if (dominoes[i] == '.') continue;
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q.emplace(i);
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time[i] = 0;
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force[i].push_back(dominoes[i]);
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}
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string ans(n, '.');
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while (!q.empty())
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{
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int i = q.front();
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q.pop();
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if (force[i].size() == 1)
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{
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char f = force[i][0];
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ans[i] = f;
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int j = (f == 'L') ? (i - 1) : (i + 1);
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if (j >= 0 && j < n)
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{
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int t = time[i];
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if (time[j] == -1)
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{
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q.emplace(j);
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time[j] = t + 1;
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force[j].push_back(f);
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}
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else if(time[j] == t + 1) force[j].push_back(f);
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}
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}
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}
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return ans;
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}
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};
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```
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### **Go**
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```go
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func pushDominoes(dominoes string) string {
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n := len(dominoes)
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q := []int{}
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time := make([]int, n)
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for i := range time {
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time[i] = -1
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}
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force := make([][]byte, n)
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for i, c := range dominoes {
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if c != '.' {
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q = append(q, i)
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time[i] = 0
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force[i] = append(force[i], byte(c))
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}
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}
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ans := bytes.Repeat([]byte{'.'}, n)
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for len(q) > 0 {
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i := q[0]
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q = q[1:]
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if len(force[i]) > 1 {
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continue
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}
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f := force[i][0]
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ans[i] = f
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j := i - 1
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if f == 'R' {
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j = i + 1
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}
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if 0 <= j && j < n {
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t := time[i]
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if time[j] == -1 {
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q = append(q, j)
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time[j] = t + 1
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force[j] = append(force[j], f)
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} else if time[j] == t+1 {
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force[j] = append(force[j], f)
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}
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}
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}
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return string(ans)
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}
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```
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### **...**

‎solution/0800-0899/0838.Push Dominoes/README_EN.md

Lines changed: 159 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -58,13 +58,171 @@
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### **Python3**
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```python
61-
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class Solution:
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def pushDominoes(self, dominoes: str) -> str:
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n = len(dominoes)
64+
q = deque()
65+
time = [-1] * n
66+
force = defaultdict(list)
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for i, f in enumerate(dominoes):
68+
if f != '.':
69+
q.append(i)
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time[i] = 0
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force[i].append(f)
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ans = ['.'] * n
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while q:
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i = q.popleft()
75+
if len(force[i]) == 1:
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ans[i] = f = force[i][0]
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j = i - 1 if f == 'L' else i + 1
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if 0 <= j < n:
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t = time[i]
80+
if time[j] == -1:
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q.append(j)
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time[j] = t + 1
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force[j].append(f)
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elif time[j] == t + 1:
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force[j].append(f)
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return ''.join(ans)
6287
```
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### **Java**
6590

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```java
92+
class Solution {
93+
public String pushDominoes(String dominoes) {
94+
int n = dominoes.length();
95+
Deque<Integer> q = new ArrayDeque<>();
96+
int[] time = new int[n];
97+
Arrays.fill(time, -1);
98+
List<Character>[] force = new List[n];
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for (int i = 0; i < n; ++i) {
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force[i] = new ArrayList<>();
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}
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for (int i = 0; i < n; ++i) {
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char f = dominoes.charAt(i);
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if (f != '.') {
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q.offer(i);
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time[i] = 0;
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force[i].add(f);
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}
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}
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char[] ans = new char[n];
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Arrays.fill(ans, '.');
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while (!q.isEmpty()) {
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int i = q.poll();
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if (force[i].size() == 1) {
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ans[i] = force[i].get(0);
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char f = ans[i];
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int j = f == 'L' ? i - 1 : i + 1;
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if (j >= 0 && j < n) {
119+
int t = time[i];
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if (time[j] == -1) {
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q.offer(j);
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time[j] = t + 1;
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force[j].add(f);
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} else if (time[j] == t + 1) {
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force[j].add(f);
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}
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}
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}
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}
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return new String(ans);
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}
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}
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```
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### **C++**
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137+
```cpp
138+
class Solution {
139+
public:
140+
string pushDominoes(string dominoes) {
141+
int n = dominoes.size();
142+
queue<int> q;
143+
vector<int> time(n, - 1);
144+
vector<string> force(n);
145+
for (int i = 0; i < n; i++)
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{
147+
if (dominoes[i] == '.') continue;
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q.emplace(i);
149+
time[i] = 0;
150+
force[i].push_back(dominoes[i]);
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}
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string ans(n, '.');
154+
while (!q.empty())
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{
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int i = q.front();
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q.pop();
158+
if (force[i].size() == 1)
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{
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char f = force[i][0];
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ans[i] = f;
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int j = (f == 'L') ? (i - 1) : (i + 1);
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if (j >= 0 && j < n)
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{
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int t = time[i];
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if (time[j] == -1)
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{
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q.emplace(j);
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time[j] = t + 1;
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force[j].push_back(f);
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}
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else if(time[j] == t + 1) force[j].push_back(f);
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}
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}
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}
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return ans;
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}
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};
179+
```
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181+
### **Go**
182+
183+
```go
184+
func pushDominoes(dominoes string) string {
185+
n := len(dominoes)
186+
q := []int{}
187+
time := make([]int, n)
188+
for i := range time {
189+
time[i] = -1
190+
}
191+
force := make([][]byte, n)
192+
for i, c := range dominoes {
193+
if c != '.' {
194+
q = append(q, i)
195+
time[i] = 0
196+
force[i] = append(force[i], byte(c))
197+
}
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}
199+
200+
ans := bytes.Repeat([]byte{'.'}, n)
201+
for len(q) > 0 {
202+
i := q[0]
203+
q = q[1:]
204+
if len(force[i]) > 1 {
205+
continue
206+
}
207+
f := force[i][0]
208+
ans[i] = f
209+
j := i - 1
210+
if f == 'R' {
211+
j = i + 1
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}
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if 0 <= j && j < n {
214+
t := time[i]
215+
if time[j] == -1 {
216+
q = append(q, j)
217+
time[j] = t + 1
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force[j] = append(force[j], f)
219+
} else if time[j] == t+1 {
220+
force[j] = append(force[j], f)
221+
}
222+
}
223+
}
224+
return string(ans)
225+
}
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```
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### **...**

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