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Commit 761336b

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feat: add solutions to lc problem: No.0990.Satisfiability of Equality Equations
1 parent 87fb929 commit 761336b

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6 files changed

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-3
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6 files changed

+405
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‎solution/0900-0999/0990.Satisfiability of Equality Equations/README.md‎

Lines changed: 174 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -59,27 +59,199 @@
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<li><code>equations[i][2]</code>&nbsp;是&nbsp;<code>&#39;=&#39;</code></li>
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</ol>
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## 解法
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<!-- 这里可写通用的实现逻辑 -->
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并查集。
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模板 1——朴素并查集:
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```python
71+
# 初始化,p存储每个点的祖宗节点
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p = [i for i in range(n)]
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# 返回x的祖宗节点
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def find(x):
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if p[x] != x:
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# 路径压缩
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p[x] = find(p[x])
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return p[x]
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# 合并a和b所在的两个集合
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p[find(a)] = find(b)
81+
```
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模板 2——维护 size 的并查集:
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```python
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# 初始化,p存储每个点的祖宗节点,size只有当节点是祖宗节点时才有意义,表示祖宗节点所在集合中,点的数量
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p = [i for i in range(n)]
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size = [1] * n
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# 返回x的祖宗节点
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def find(x):
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if p[x] != x:
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# 路径压缩
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p[x] = find(p[x])
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return p[x]
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# 合并a和b所在的两个集合
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size[find(b)] += size[find(a)]
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p[find(a)] = find(b)
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```
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模板 3——维护到祖宗节点距离的并查集:
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```python
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# 初始化,p存储每个点的祖宗节点,d[x]存储x到p[x]的距离
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p = [i for i in range(n)]
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d = [0] * n
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# 返回x的祖宗节点
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def find(x):
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if p[x] != x:
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t = find(p[x])
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d[x] += d[p[x]]
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p[x] = t
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return p[x]
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# 合并a和b所在的两个集合
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p[find(a)] = find(b)
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d[find(a)] = dinstance
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```
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对于本题,先遍历所有的等式,构造并查集。接着遍历所有不等式,如果不等式的两个变量处于同一个集合,说明发生矛盾,返回 false。否则遍历结束返回 true。
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67120
<!-- tabs:start -->
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### **Python3**
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71124
<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
74-
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class Solution:
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def equationsPossible(self, equations: List[str]) -> bool:
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p = [i for i in range(26)]
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def find(x):
132+
if p[x] != x:
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p[x] = find(p[x])
134+
return p[x]
135+
136+
for e in equations:
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a, r, b = ord(e[0]) - ord('a'), e[1:3], ord(e[3]) - ord('a')
138+
if r == '==':
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p[find(a)] = find(b)
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for e in equations:
141+
a, r, b = ord(e[0]) - ord('a'), e[1:3], ord(e[3]) - ord('a')
142+
if r == '!=' and find(a) == find(b):
143+
return False
144+
return True
75145
```
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### **Java**
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79149
<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
152+
class Solution {
153+
private int[] p;
154+
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public boolean equationsPossible(String[] equations) {
156+
p = new int[26];
157+
for (int i = 0; i < 26; ++i) {
158+
p[i] = i;
159+
}
160+
for (String e : equations) {
161+
int a = e.charAt(0) - 'a', b = e.charAt(3) - 'a';
162+
String r = e.substring(1, 3);
163+
if ("==".equals(r)) {
164+
p[find(a)] = find(b);
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}
166+
}
167+
for (String e : equations) {
168+
int a = e.charAt(0) - 'a', b = e.charAt(3) - 'a';
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String r = e.substring(1, 3);
170+
if ("!=".equals(r) && find(a) == find(b)) {
171+
return false;
172+
}
173+
}
174+
return true;
175+
}
176+
177+
private int find(int x) {
178+
if (p[x] != x) {
179+
p[x] = find(p[x]);
180+
}
181+
return p[x];
182+
}
183+
}
184+
```
185+
186+
### **C++**
187+
188+
```cpp
189+
class Solution {
190+
public:
191+
vector<int> p;
192+
193+
bool equationsPossible(vector<string>& equations) {
194+
p.resize(26);
195+
for (int i = 0; i < 26; ++i)
196+
p[i] = i;
197+
for (auto e : equations)
198+
{
199+
int a = e[0] - 'a', b = e[3] - 'a';
200+
char r = e[1];
201+
if (r == '=')
202+
p[find(a)] = find(b);
203+
}
204+
for (auto e : equations)
205+
{
206+
int a = e[0] - 'a', b = e[3] - 'a';
207+
char r = e[1];
208+
if (r == '!' && find(a) == find(b))
209+
return false;
210+
}
211+
return true;
212+
}
213+
214+
int find(int x) {
215+
if (p[x] != x)
216+
p[x] = find(p[x]);
217+
return p[x];
218+
}
219+
};
220+
```
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### **Go**
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```go
225+
var p []int
226+
227+
func equationsPossible(equations []string) bool {
228+
p = make([]int, 26)
229+
for i := 1; i < 26; i++ {
230+
p[i] = i
231+
}
232+
for _, e := range equations {
233+
a, b := int(e[0]-'a'), int(e[3]-'a')
234+
r := e[1]
235+
if r == '=' {
236+
p[find(a)] = find(b)
237+
}
238+
}
239+
for _, e := range equations {
240+
a, b := int(e[0]-'a'), int(e[3]-'a')
241+
r := e[1]
242+
if r == '!' && find(a) == find(b) {
243+
return false
244+
}
245+
}
246+
return true
247+
}
248+
249+
func find(x int) int {
250+
if p[x] != x {
251+
p[x] = find(p[x])
252+
}
253+
return p[x]
254+
}
83255
```
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85257
### **...**

‎solution/0900-0999/0990.Satisfiability of Equality Equations/README_EN.md‎

Lines changed: 120 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -141,13 +141,132 @@
141141
### **Python3**
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143143
```python
144-
144+
class Solution:
145+
def equationsPossible(self, equations: List[str]) -> bool:
146+
p = [i for i in range(26)]
147+
148+
def find(x):
149+
if p[x] != x:
150+
p[x] = find(p[x])
151+
return p[x]
152+
153+
for e in equations:
154+
a, r, b = ord(e[0]) - ord('a'), e[1:3], ord(e[3]) - ord('a')
155+
if r == '==':
156+
p[find(a)] = find(b)
157+
for e in equations:
158+
a, r, b = ord(e[0]) - ord('a'), e[1:3], ord(e[3]) - ord('a')
159+
if r == '!=' and find(a) == find(b):
160+
return False
161+
return True
145162
```
146163

147164
### **Java**
148165

149166
```java
167+
class Solution {
168+
private int[] p;
169+
170+
public boolean equationsPossible(String[] equations) {
171+
p = new int[26];
172+
for (int i = 0; i < 26; ++i) {
173+
p[i] = i;
174+
}
175+
for (String e : equations) {
176+
int a = e.charAt(0) - 'a', b = e.charAt(3) - 'a';
177+
String r = e.substring(1, 3);
178+
if ("==".equals(r)) {
179+
p[find(a)] = find(b);
180+
}
181+
}
182+
for (String e : equations) {
183+
int a = e.charAt(0) - 'a', b = e.charAt(3) - 'a';
184+
String r = e.substring(1, 3);
185+
if ("!=".equals(r) && find(a) == find(b)) {
186+
return false;
187+
}
188+
}
189+
return true;
190+
}
191+
192+
private int find(int x) {
193+
if (p[x] != x) {
194+
p[x] = find(p[x]);
195+
}
196+
return p[x];
197+
}
198+
}
199+
```
200+
201+
### **C++**
202+
203+
```cpp
204+
class Solution {
205+
public:
206+
vector<int> p;
207+
208+
bool equationsPossible(vector<string>& equations) {
209+
p.resize(26);
210+
for (int i = 0; i < 26; ++i)
211+
p[i] = i;
212+
for (auto e : equations)
213+
{
214+
int a = e[0] - 'a', b = e[3] - 'a';
215+
char r = e[1];
216+
if (r == '=')
217+
p[find(a)] = find(b);
218+
}
219+
for (auto e : equations)
220+
{
221+
int a = e[0] - 'a', b = e[3] - 'a';
222+
char r = e[1];
223+
if (r == '!' && find(a) == find(b))
224+
return false;
225+
}
226+
return true;
227+
}
228+
229+
int find(int x) {
230+
if (p[x] != x)
231+
p[x] = find(p[x]);
232+
return p[x];
233+
}
234+
};
235+
```
150236

237+
### **Go**
238+
239+
```go
240+
var p []int
241+
242+
func equationsPossible(equations []string) bool {
243+
p = make([]int, 26)
244+
for i := 1; i < 26; i++ {
245+
p[i] = i
246+
}
247+
for _, e := range equations {
248+
a, b := int(e[0]-'a'), int(e[3]-'a')
249+
r := e[1]
250+
if r == '=' {
251+
p[find(a)] = find(b)
252+
}
253+
}
254+
for _, e := range equations {
255+
a, b := int(e[0]-'a'), int(e[3]-'a')
256+
r := e[1]
257+
if r == '!' && find(a) == find(b) {
258+
return false
259+
}
260+
}
261+
return true
262+
}
263+
264+
func find(x int) int {
265+
if p[x] != x {
266+
p[x] = find(p[x])
267+
}
268+
return p[x]
269+
}
151270
```
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153272
### **...**
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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,31 @@
1+
class Solution {
2+
public:
3+
vector<int> p;
4+
5+
bool equationsPossible(vector<string>& equations) {
6+
p.resize(26);
7+
for (int i = 0; i < 26; ++i)
8+
p[i] = i;
9+
for (auto e : equations)
10+
{
11+
int a = e[0] - 'a', b = e[3] - 'a';
12+
char r = e[1];
13+
if (r == '=')
14+
p[find(a)] = find(b);
15+
}
16+
for (auto e : equations)
17+
{
18+
int a = e[0] - 'a', b = e[3] - 'a';
19+
char r = e[1];
20+
if (r == '!' && find(a) == find(b))
21+
return false;
22+
}
23+
return true;
24+
}
25+
26+
int find(int x) {
27+
if (p[x] != x)
28+
p[x] = find(p[x]);
29+
return p[x];
30+
}
31+
};

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