56. Merge Intervals

Given an array of `intervals` where `intervals[i] = [starti, endi]`, merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input.

Example 1:

```Input: intervals = [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].
```

Example 2:

```Input: intervals = [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.
```

Constraints:

• `1 <= intervals.length <= 104`
• `intervals[i].length == 2`
• `0 <= starti <= endi <= 104`

56. Merge Intervals
``````struct Solution;

impl Solution {
fn merge(mut intervals: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
intervals.sort_unstable_by(|a, b| a[0].cmp(&b[0]));
let mut res: Vec<Vec<i32>> = vec![];
let mut temp: Option<Vec<i32>> = None;
for v in intervals {
if let Some(t) = temp.clone() {
if v[0] <= t[1] {
temp = Some(vec![t[0], i32::max(t[1], v[1])]);
} else {
temp = Some(v);
res.push(t);
}
} else {
temp = Some(v);
}
}
if let Some(t) = temp {
res.push(t);
}
res
}
}

#[test]
fn test() {
let intervals: Vec<Vec<i32>> = vec_vec_i32![[1, 3], [2, 6], [8, 10], [15, 18]];
let res: Vec<Vec<i32>> = vec_vec_i32![[1, 6], [8, 10], [15, 18]];
assert_eq!(Solution::merge(intervals), res);
let intervals: Vec<Vec<i32>> = vec_vec_i32![[1, 4], [4, 5]];
let res: Vec<Vec<i32>> = vec_vec_i32![[1, 5]];
assert_eq!(Solution::merge(intervals), res);
}
``````