## 1042. Flower Planting With No Adjacent

You have `n` gardens, labeled from `1` to `n`, and an array `paths` where `paths[i] = [xi, yi]` describes a bidirectional path between garden `xi` to garden `yi`. In each garden, you want to plant one of 4 types of flowers.

All gardens have at most 3 paths coming into or leaving it.

Your task is to choose a flower type for each garden such that, for any two gardens connected by a path, they have different types of flowers.

Return any such a choice as an array `answer`, where `answer[i]` is the type of flower planted in the `(i+1)th` garden. The flower types are denoted `1`, `2`, `3`, or `4`. It is guaranteed an answer exists.

Example 1:

```Input: n = 3, paths = [[1,2],[2,3],[3,1]]
Output: [1,2,3]
Explanation:
Gardens 1 and 2 have different types.
Gardens 2 and 3 have different types.
Gardens 3 and 1 have different types.
Hence, [1,2,3] is a valid answer. Other valid answers include [1,2,4], [1,4,2], and [3,2,1].
```

Example 2:

```Input: n = 4, paths = [[1,2],[3,4]]
Output: [1,2,1,2]
```

Example 3:

```Input: n = 4, paths = [[1,2],[2,3],[3,4],[4,1],[1,3],[2,4]]
Output: [1,2,3,4]
```

Constraints:

• `1 <= n <= 104`
• `0 <= paths.length <= 2 * 104`
• `paths[i].length == 2`
• `1 <= xi, yi <= n`
• `xi != yi`
• Every garden has at most 3 paths coming into or leaving it.

## Rust Solution

``````struct Solution;

impl Solution {
fn garden_no_adj(n: i32, paths: Vec<Vec<i32>>) -> Vec<i32> {
let n = n as usize;
let mut g: Vec<Vec<usize>> = vec![vec![]; n];
for path in paths {
let u = (path - 1) as usize;
let v = (path - 1) as usize;
g[u].push(v);
g[v].push(u);
}
let mut colors: Vec<i32> = vec![0; n];
for i in 0..n {
let mut used: Vec<bool> = vec![false; 5];
for &j in &g[i] {
used[colors[j] as usize] = true;
}
for c in 1..5 {
if !used[c] {
colors[i] = c as i32;
break;
}
}
}
colors
}
}

#[test]
fn test() {
let n = 3;
let paths: Vec<Vec<i32>> = vec_vec_i32![[1, 2], [2, 3], [3, 1]];
let res = vec![1, 2, 3];