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feat: add solutions to lc problems: No.3483,3484,3487 #4254

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Mar 17, 2025
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feat: add solutions to lc problems: No.3483,3484,3487 #4254

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117 changes: 113 additions & 4 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -75,32 +75,141 @@ edit_url: https://github.com/doocs/leetcode/edit/main/solution/3400-3499/3483.Un

<!-- solution:start -->

### 方法一
### 方法一：哈希表 + 枚举

我们用一个哈希表 $\textit{s}$ 记录所有不同的三位偶数，然后枚举所有可能的三位偶数，将其加入哈希表中。

最后返回哈希表的大小即可。

时间复杂度 $O(n^3)$，空间复杂度 $O(n^3)$。其中 $n$ 为数组 $\textit{digits}$ 的长度。

<!-- tabs:start -->

#### Python3

```python

class Solution:
def totalNumbers(self, digits: List[int]) -> int:
s = set()
for i, a in enumerate(digits):
if a & 1:
continue
for j, b in enumerate(digits):
if i == j:
continue
for k, c in enumerate(digits):
if c == 0 or k in (i, j):
continue
s.add(c * 100 + b * 10 + a)
return len(s)
```

#### Java

```java

class Solution {
public int totalNumbers(int[] digits) {
Set<Integer> s = new HashSet<>();
int n = digits.length;
for (int i = 0; i < n; ++i) {
if (digits[i] % 2 == 1) {
continue;
}
for (int j = 0; j < n; ++j) {
if (i == j) {
continue;
}
for (int k = 0; k < n; ++k) {
if (digits[k] == 0 || k == i || k == j) {
continue;
}
s.add(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size();
}
}
```

#### C++

```cpp

class Solution {
public:
int totalNumbers(vector<int>& digits) {
unordered_set<int> s;
int n = digits.size();
for (int i = 0; i < n; ++i) {
if (digits[i] % 2 == 1) {
continue;
}
for (int j = 0; j < n; ++j) {
if (i == j) {
continue;
}
for (int k = 0; k < n; ++k) {
if (digits[k] == 0 || k == i || k == j) {
continue;
}
s.insert(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size();
}
};
```

#### Go

```go
func totalNumbers(digits []int) int {
s := make(map[int]struct{})
for i, a := range digits {
if a%2 == 1 {
continue
}
for j, b := range digits {
if i == j {
continue
}
for k, c := range digits {
if c == 0 || k == i || k == j {
continue
}
s[c*100+b*10+a] = struct{}{}
}
}
}
return len(s)
}
```

#### TypeScript

```ts
function totalNumbers(digits: number[]): number {
const s = new Set<number>();
const n = digits.length;
for (let i = 0; i < n; ++i) {
if (digits[i] % 2 === 1) {
continue;
}
for (let j = 0; j < n; ++j) {
if (i === j) {
continue;
}
for (let k = 0; k < n; ++k) {
if (digits[k] === 0 || k === i || k === j) {
continue;
}
s.add(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size;
}
```

<!-- tabs:end -->
Expand Down
117 changes: 113 additions & 4 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/README_EN.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -73,32 +73,141 @@ edit_url: https://github.com/doocs/leetcode/edit/main/solution/3400-3499/3483.Un

<!-- solution:start -->

### Solution 1
### Solution 1: Hash Set + Enumeration

We use a hash set $\textit{s}$ to record all distinct three-digit even numbers, and then enumerate all possible three-digit even numbers to add them to the hash set.

Finally, we return the size of the hash set.

The time complexity is $O(n^3)$, and the space complexity is $O(n^3)$. Where $n$ is the length of the array $\textit{digits}$.

<!-- tabs:start -->

#### Python3

```python

class Solution:
def totalNumbers(self, digits: List[int]) -> int:
s = set()
for i, a in enumerate(digits):
if a & 1:
continue
for j, b in enumerate(digits):
if i == j:
continue
for k, c in enumerate(digits):
if c == 0 or k in (i, j):
continue
s.add(c * 100 + b * 10 + a)
return len(s)
```

#### Java

```java

class Solution {
public int totalNumbers(int[] digits) {
Set<Integer> s = new HashSet<>();
int n = digits.length;
for (int i = 0; i < n; ++i) {
if (digits[i] % 2 == 1) {
continue;
}
for (int j = 0; j < n; ++j) {
if (i == j) {
continue;
}
for (int k = 0; k < n; ++k) {
if (digits[k] == 0 || k == i || k == j) {
continue;
}
s.add(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size();
}
}
```

#### C++

```cpp

class Solution {
public:
int totalNumbers(vector<int>& digits) {
unordered_set<int> s;
int n = digits.size();
for (int i = 0; i < n; ++i) {
if (digits[i] % 2 == 1) {
continue;
}
for (int j = 0; j < n; ++j) {
if (i == j) {
continue;
}
for (int k = 0; k < n; ++k) {
if (digits[k] == 0 || k == i || k == j) {
continue;
}
s.insert(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size();
}
};
```

#### Go

```go
func totalNumbers(digits []int) int {
s := make(map[int]struct{})
for i, a := range digits {
if a%2 == 1 {
continue
}
for j, b := range digits {
if i == j {
continue
}
for k, c := range digits {
if c == 0 || k == i || k == j {
continue
}
s[c*100+b*10+a] = struct{}{}
}
}
}
return len(s)
}
```

#### TypeScript

```ts
function totalNumbers(digits: number[]): number {
const s = new Set<number>();
const n = digits.length;
for (let i = 0; i < n; ++i) {
if (digits[i] % 2 === 1) {
continue;
}
for (let j = 0; j < n; ++j) {
if (i === j) {
continue;
}
for (let k = 0; k < n; ++k) {
if (digits[k] === 0 || k === i || k === j) {
continue;
}
s.add(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size;
}
```

<!-- tabs:end -->
Expand Down
24 changes: 24 additions & 0 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/Solution.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,24 @@
class Solution {
public:
int totalNumbers(vector<int>& digits) {
unordered_set<int> s;
int n = digits.size();
for (int i = 0; i < n; ++i) {
if (digits[i] % 2 == 1) {
continue;
}
for (int j = 0; j < n; ++j) {
if (i == j) {
continue;
}
for (int k = 0; k < n; ++k) {
if (digits[k] == 0 || k == i || k == j) {
continue;
}
s.insert(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size();
}
};
20 changes: 20 additions & 0 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/Solution.go
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
func totalNumbers(digits []int) int {
s := make(map[int]struct{})
for i, a := range digits {
if a%2 == 1 {
continue
}
for j, b := range digits {
if i == j {
continue
}
for k, c := range digits {
if c == 0 || k == i || k == j {
continue
}
s[c*100+b*10+a] = struct{}{}
}
}
}
return len(s)
}
23 changes: 23 additions & 0 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/Solution.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
class Solution {
public int totalNumbers(int[] digits) {
Set<Integer> s = new HashSet<>();
int n = digits.length;
for (int i = 0; i < n; ++i) {
if (digits[i] % 2 == 1) {
continue;
}
for (int j = 0; j < n; ++j) {
if (i == j) {
continue;
}
for (int k = 0; k < n; ++k) {
if (digits[k] == 0 || k == i || k == j) {
continue;
}
s.add(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size();
}
}
14 changes: 14 additions & 0 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/Solution.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,14 @@
class Solution:
def totalNumbers(self, digits: List[int]) -> int:
s = set()
for i, a in enumerate(digits):
if a & 1:
continue
for j, b in enumerate(digits):
if i == j:
continue
for k, c in enumerate(digits):
if c == 0 or k in (i, j):
continue
s.add(c * 100 + b * 10 + a)
return len(s)
21 changes: 21 additions & 0 deletions solution/3400-3499/3483.Unique 3-Digit Even Numbers/Solution.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,21 @@
function totalNumbers(digits: number[]): number {
const s = new Set<number>();
const n = digits.length;
for (let i = 0; i < n; ++i) {
if (digits[i] % 2 === 1) {
continue;
}
for (let j = 0; j < n; ++j) {
if (i === j) {
continue;
}
for (let k = 0; k < n; ++k) {
if (digits[k] === 0 || k === i || k === j) {
continue;
}
s.add(digits[k] * 100 + digits[j] * 10 + digits[i]);
}
}
}
return s.size;
}
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