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Commit 778311f

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feat: add solutions to lc problem: No.0784
No.0784.Letter Case Permutation
1 parent bcaf0c5 commit 778311f

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4 files changed

+224
-2
lines changed

4 files changed

+224
-2
lines changed

‎solution/0700-0799/0784.Letter Case Permutation/README.md‎

Lines changed: 89 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -30,27 +30,115 @@
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<li><code>S</code>&nbsp;仅由数字和字母组成。</li>
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</ul>
3232

33-
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## 解法
3534

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<!-- 这里可写通用的实现逻辑 -->
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DFS 回溯法。
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3839
<!-- 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:
47+
def letterCasePermutation(self, s: str) -> List[str]:
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def dfs(i, t):
49+
if i == len(t):
50+
ans.append(''.join(t))
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return
52+
dfs(i + 1, t)
53+
if t[i].isalpha():
54+
t[i] = t[i].upper() if t[i].islower() else t[i].lower()
55+
dfs(i + 1, t)
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ans = []
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t = list(s)
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dfs(0, t)
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return ans
61+
```
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```python
64+
class Solution:
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def letterCasePermutation(self, s: str) -> List[str]:
66+
def dfs(i, t):
67+
if i == len(s):
68+
ans.append(t)
69+
return
70+
if s[i].isalpha():
71+
dfs(i + 1, t + s[i].upper())
72+
dfs(i + 1, t + s[i].lower())
73+
else:
74+
dfs(i + 1, t + s[i])
75+
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ans = []
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dfs(0, '')
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return ans
4679
```
4780

4881
### **Java**
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5083
<!-- 这里可写当前语言的特殊实现逻辑 -->
5184

5285
```java
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class Solution {
87+
public List<String> letterCasePermutation(String S) {
88+
char[] cs = S.toCharArray();
89+
List<String> res = new ArrayList<>();
90+
dfs(cs, 0, res);
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return res;
92+
}
93+
94+
private void dfs(char[] cs, int i, List<String> res) {
95+
if (i == cs.length) {
96+
res.add(String.valueOf(cs));
97+
return;
98+
}
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dfs(cs, i + 1, res);
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if (cs[i] >= 'A') {
101+
cs[i] ^= 32;
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dfs(cs, i + 1, res);
103+
}
104+
}
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}
106+
```
53107

108+
### **C++**
109+
110+
```cpp
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class Solution {
112+
public:
113+
vector<string> ans;
114+
string s;
115+
116+
vector<string> letterCasePermutation(string s) {
117+
this->s = s;
118+
string t = "";
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dfs(0, t);
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return ans;
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}
122+
123+
void dfs(int i, string t) {
124+
if (i == s.size())
125+
{
126+
ans.push_back(t);
127+
return;
128+
}
129+
if (isalpha(s[i]))
130+
{
131+
char c1 = toupper(s[i]);
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char c2 = tolower(s[i]);
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dfs(i + 1, t + c1);
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dfs(i + 1, t + c2);
135+
}
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else
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{
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dfs(i + 1, t + s[i]);
139+
}
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}
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};
54142
```
55143
56144
### **...**

‎solution/0700-0799/0784.Letter Case Permutation/README_EN.md‎

Lines changed: 89 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -45,21 +45,109 @@
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<li><code>S</code> will consist only of letters or digits.</li>
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</ul>
4747

48-
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## Solutions
5049

50+
DFS.
51+
5152
<!-- tabs:start -->
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5354
### **Python3**
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5556
```python
57+
class Solution:
58+
def letterCasePermutation(self, s: str) -> List[str]:
59+
def dfs(i, t):
60+
if i == len(t):
61+
ans.append(''.join(t))
62+
return
63+
dfs(i + 1, t)
64+
if t[i].isalpha():
65+
t[i] = t[i].upper() if t[i].islower() else t[i].lower()
66+
dfs(i + 1, t)
67+
68+
ans = []
69+
t = list(s)
70+
dfs(0, t)
71+
return ans
72+
```
5673

74+
```python
75+
class Solution:
76+
def letterCasePermutation(self, s: str) -> List[str]:
77+
def dfs(i, t):
78+
if i == len(s):
79+
ans.append(t)
80+
return
81+
if s[i].isalpha():
82+
dfs(i + 1, t + s[i].upper())
83+
dfs(i + 1, t + s[i].lower())
84+
else:
85+
dfs(i + 1, t + s[i])
86+
87+
ans = []
88+
dfs(0, '')
89+
return ans
5790
```
5891

5992
### **Java**
6093

6194
```java
95+
class Solution {
96+
public List<String> letterCasePermutation(String S) {
97+
char[] cs = S.toCharArray();
98+
List<String> res = new ArrayList<>();
99+
dfs(cs, 0, res);
100+
return res;
101+
}
102+
103+
private void dfs(char[] cs, int i, List<String> res) {
104+
if (i == cs.length) {
105+
res.add(String.valueOf(cs));
106+
return;
107+
}
108+
dfs(cs, i + 1, res);
109+
if (cs[i] >= 'A') {
110+
cs[i] ^= 32;
111+
dfs(cs, i + 1, res);
112+
}
113+
}
114+
}
115+
```
62116

117+
### **C++**
118+
119+
```cpp
120+
class Solution {
121+
public:
122+
vector<string> ans;
123+
string s;
124+
125+
vector<string> letterCasePermutation(string s) {
126+
this->s = s;
127+
string t = "";
128+
dfs(0, t);
129+
return ans;
130+
}
131+
132+
void dfs(int i, string t) {
133+
if (i == s.size())
134+
{
135+
ans.push_back(t);
136+
return;
137+
}
138+
if (isalpha(s[i]))
139+
{
140+
char c1 = toupper(s[i]);
141+
char c2 = tolower(s[i]);
142+
dfs(i + 1, t + c1);
143+
dfs(i + 1, t + c2);
144+
}
145+
else
146+
{
147+
dfs(i + 1, t + s[i]);
148+
}
149+
}
150+
};
63151
```
64152
65153
### **...**
Lines changed: 31 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,31 @@
1+
class Solution {
2+
public:
3+
vector<string> ans;
4+
string s;
5+
6+
vector<string> letterCasePermutation(string s) {
7+
this->s = s;
8+
string t = "";
9+
dfs(0, t);
10+
return ans;
11+
}
12+
13+
void dfs(int i, string t) {
14+
if (i == s.size())
15+
{
16+
ans.push_back(t);
17+
return;
18+
}
19+
if (isalpha(s[i]))
20+
{
21+
char c1 = toupper(s[i]);
22+
char c2 = tolower(s[i]);
23+
dfs(i + 1, t + c1);
24+
dfs(i + 1, t + c2);
25+
}
26+
else
27+
{
28+
dfs(i + 1, t + s[i]);
29+
}
30+
}
31+
};
Lines changed: 15 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,15 @@
1+
class Solution:
2+
def letterCasePermutation(self, s: str) -> List[str]:
3+
def dfs(i, t):
4+
if i == len(t):
5+
ans.append(''.join(t))
6+
return
7+
dfs(i + 1, t)
8+
if t[i].isalpha():
9+
t[i] = t[i].upper() if t[i].islower() else t[i].lower()
10+
dfs(i + 1, t)
11+
12+
ans = []
13+
t = list(s)
14+
dfs(0, t)
15+
return ans

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