Skip to content

feat: add solutions to lc problems: No.1260+ #2437

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Mar 12, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ class FindElements {
root->val = 0;
dfs(root);
}

bool find(int target) {
return s.contains(target);
}
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,7 @@ public FindElements(TreeNode root) {
root.val = 0;
dfs(root);
}

public boolean find(int target) {
return s.contains(target);
}
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,7 @@

由于题目中的 $n$ 范围较小,我们也可以直接创建一个大小为 $n+1$ 的数组来存放数据,运行效率较高。

时间复杂度 $O(n)$,空间复杂度 $O(n)$。
时间复杂度 $O(n)$,空间复杂度 $O(n)$。其中 $n$ 为 $groupSizes$ 的长度。

<!-- tabs:start -->

Expand Down Expand Up @@ -95,7 +95,9 @@ public:
vector<vector<int>> groupThePeople(vector<int>& groupSizes) {
int n = groupSizes.size();
vector<vector<int>> g(n + 1);
for (int i = 0; i < n; ++i) g[groupSizes[i]].push_back(i);
for (int i = 0; i < n; ++i) {
g[groupSizes[i]].push_back(i);
}
vector<vector<int>> ans;
for (int i = 0; i < g.size(); ++i) {
for (int j = 0; j < g[i].size(); j += i) {
Expand Down Expand Up @@ -127,82 +129,49 @@ func groupThePeople(groupSizes []int) [][]int {

```ts
function groupThePeople(groupSizes: number[]): number[][] {
const res = [];
const map = new Map<number, number[]>();
const n = groupSizes.length;
for (let i = 0; i < n; i++) {
const size = groupSizes[i];
map.set(size, [...(map.get(size) ?? []), i]);
const arr = map.get(size);
if (arr.length === size) {
res.push(arr);
map.set(size, []);
const n: number = groupSizes.length;
const g: number[][] = Array.from({ length: n + 1 }, () => []);

for (let i = 0; i < groupSizes.length; i++) {
const size: number = groupSizes[i];
g[size].push(i);
}
const ans: number[][] = [];
for (let i = 1; i <= n; i++) {
const group: number[] = [];
for (let j = 0; j < g[i].length; j += i) {
group.push(...g[i].slice(j, j + i));
ans.push([...group]);
group.length = 0;
}
}
return res;
return ans;
}
```

```rust
use std::collections::HashMap;
impl Solution {
pub fn group_the_people(group_sizes: Vec<i32>) -> Vec<Vec<i32>> {
let mut res = vec![];
let mut map = HashMap::new();
for i in 0..group_sizes.len() {
let size = group_sizes[i] as usize;
let arr = map.entry(size).or_insert(vec![]);
arr.push(i as i32);
if arr.len() == size {
res.push(arr.clone());
arr.clear();
}
}
res
}
}
```

<!-- tabs:end -->

### 方法二
let n: usize = group_sizes.len();
let mut g: Vec<Vec<usize>> = vec![Vec::new(); n + 1];

<!-- tabs:start -->

```python
class Solution:
def groupThePeople(self, groupSizes: List[int]) -> List[List[int]]:
g = defaultdict(list)
for i, x in enumerate(groupSizes):
g[x].append(i)
ans = []
for x, idx in g.items():
t = []
for i in idx:
t.append(i)
if len(t) == x:
ans.append(t)
t = []
return ans
```
for (i, &size) in group_sizes.iter().enumerate() {
g[size as usize].push(i);
}

```rust
impl Solution {
#[allow(dead_code)]
pub fn group_the_people(group_sizes: Vec<i32>) -> Vec<Vec<i32>> {
let n = group_sizes.len();
let mut g = vec![vec![]; n + 1];
let mut ret = vec![];

for i in 0..n {
g[group_sizes[i] as usize].push(i as i32);
if g[group_sizes[i] as usize].len() == (group_sizes[i] as usize) {
ret.push(g[group_sizes[i] as usize].clone());
g[group_sizes[i] as usize].clear();
let mut ans: Vec<Vec<i32>> = Vec::new();
for (i, v) in g.into_iter().enumerate() {
for j in (0..v.len()).step_by(i.max(1)) {
ans.push(
v[j..(j + i).min(v.len())]
.iter()
.map(|&x| x as i32)
.collect()
);
}
}

ret
ans
}
}
```
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,13 @@ Other possible solutions are [[2,1,6],[5],[0,4,3]] and [[5],[0,6,2],[4,3,1]].

## Solutions

### Solution 1
### Solution 1: Hash Table or Array

We use a hash table $g$ to store which people are in each group size $groupSize$. Then we partition each group size into $k$ equal parts, with each part containing $groupSize$ people.

Since the range of $n$ in the problem is small, we can also directly create an array of size $n+1$ to store the data, which is more efficient.

Time complexity is $O(n)$, and space complexity is $O(n)$. Here, $n$ is the length of $groupSizes$.

<!-- tabs:start -->

Expand Down Expand Up @@ -85,7 +91,9 @@ public:
vector<vector<int>> groupThePeople(vector<int>& groupSizes) {
int n = groupSizes.size();
vector<vector<int>> g(n + 1);
for (int i = 0; i < n; ++i) g[groupSizes[i]].push_back(i);
for (int i = 0; i < n; ++i) {
g[groupSizes[i]].push_back(i);
}
vector<vector<int>> ans;
for (int i = 0; i < g.size(); ++i) {
for (int j = 0; j < g[i].size(); j += i) {
Expand Down Expand Up @@ -117,82 +125,49 @@ func groupThePeople(groupSizes []int) [][]int {

```ts
function groupThePeople(groupSizes: number[]): number[][] {
const res = [];
const map = new Map<number, number[]>();
const n = groupSizes.length;
for (let i = 0; i < n; i++) {
const size = groupSizes[i];
map.set(size, [...(map.get(size) ?? []), i]);
const arr = map.get(size);
if (arr.length === size) {
res.push(arr);
map.set(size, []);
const n: number = groupSizes.length;
const g: number[][] = Array.from({ length: n + 1 }, () => []);

for (let i = 0; i < groupSizes.length; i++) {
const size: number = groupSizes[i];
g[size].push(i);
}
const ans: number[][] = [];
for (let i = 1; i <= n; i++) {
const group: number[] = [];
for (let j = 0; j < g[i].length; j += i) {
group.push(...g[i].slice(j, j + i));
ans.push([...group]);
group.length = 0;
}
}
return res;
return ans;
}
```

```rust
use std::collections::HashMap;
impl Solution {
pub fn group_the_people(group_sizes: Vec<i32>) -> Vec<Vec<i32>> {
let mut res = vec![];
let mut map = HashMap::new();
for i in 0..group_sizes.len() {
let size = group_sizes[i] as usize;
let arr = map.entry(size).or_insert(vec![]);
arr.push(i as i32);
if arr.len() == size {
res.push(arr.clone());
arr.clear();
}
}
res
}
}
```

<!-- tabs:end -->

### Solution 2

<!-- tabs:start -->
let n: usize = group_sizes.len();
let mut g: Vec<Vec<usize>> = vec![Vec::new(); n + 1];

```python
class Solution:
def groupThePeople(self, groupSizes: List[int]) -> List[List[int]]:
g = defaultdict(list)
for i, x in enumerate(groupSizes):
g[x].append(i)
ans = []
for x, idx in g.items():
t = []
for i in idx:
t.append(i)
if len(t) == x:
ans.append(t)
t = []
return ans
```
for (i, &size) in group_sizes.iter().enumerate() {
g[size as usize].push(i);
}

```rust
impl Solution {
#[allow(dead_code)]
pub fn group_the_people(group_sizes: Vec<i32>) -> Vec<Vec<i32>> {
let n = group_sizes.len();
let mut g = vec![vec![]; n + 1];
let mut ret = vec![];

for i in 0..n {
g[group_sizes[i] as usize].push(i as i32);
if g[group_sizes[i] as usize].len() == (group_sizes[i] as usize) {
ret.push(g[group_sizes[i] as usize].clone());
g[group_sizes[i] as usize].clear();
let mut ans: Vec<Vec<i32>> = Vec::new();
for (i, v) in g.into_iter().enumerate() {
for j in (0..v.len()).step_by(i.max(1)) {
ans.push(
v[j..(j + i).min(v.len())]
.iter()
.map(|&x| x as i32)
.collect()
);
}
}

ret
ans
}
}
```
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,9 @@ class Solution {
vector<vector<int>> groupThePeople(vector<int>& groupSizes) {
int n = groupSizes.size();
vector<vector<int>> g(n + 1);
for (int i = 0; i < n; ++i) g[groupSizes[i]].push_back(i);
for (int i = 0; i < n; ++i) {
g[groupSizes[i]].push_back(i);
}
vector<vector<int>> ans;
for (int i = 0; i < g.size(); ++i) {
for (int j = 0; j < g[i].size(); j += i) {
Expand Down
Original file line number Diff line number Diff line change
@@ -1,17 +1,24 @@
use std::collections::HashMap;
impl Solution {
pub fn group_the_people(group_sizes: Vec<i32>) -> Vec<Vec<i32>> {
let mut res = vec![];
let mut map = HashMap::new();
for i in 0..group_sizes.len() {
let size = group_sizes[i] as usize;
let arr = map.entry(size).or_insert(vec![]);
arr.push(i as i32);
if arr.len() == size {
res.push(arr.clone());
arr.clear();
let n: usize = group_sizes.len();
let mut g: Vec<Vec<usize>> = vec![Vec::new(); n + 1];

for (i, &size) in group_sizes.iter().enumerate() {
g[size as usize].push(i);
}

let mut ans: Vec<Vec<i32>> = Vec::new();
for (i, v) in g.into_iter().enumerate() {
for j in (0..v.len()).step_by(i.max(1)) {
ans.push(
v[j..(j + i).min(v.len())]
.iter()
.map(|&x| x as i32)
.collect()
);
}
}
res

ans
}
}
Original file line number Diff line number Diff line change
@@ -1,15 +1,19 @@
function groupThePeople(groupSizes: number[]): number[][] {
const res = [];
const map = new Map<number, number[]>();
const n = groupSizes.length;
for (let i = 0; i < n; i++) {
const size = groupSizes[i];
map.set(size, [...(map.get(size) ?? []), i]);
const arr = map.get(size);
if (arr.length === size) {
res.push(arr);
map.set(size, []);
const n: number = groupSizes.length;
const g: number[][] = Array.from({ length: n + 1 }, () => []);

for (let i = 0; i < groupSizes.length; i++) {
const size: number = groupSizes[i];
g[size].push(i);
}
const ans: number[][] = [];
for (let i = 1; i <= n; i++) {
const group: number[] = [];
for (let j = 0; j < g[i].length; j += i) {
group.push(...g[i].slice(j, j + i));
ans.push([...group]);
group.length = 0;
}
}
return res;
return ans;
}

This file was deleted.

Loading