0057 - Insert Interval (Medium)
Problem Link
https://leetcode.com/problems/insert-interval/
Problem Statement
You are given an array of non-overlapping intervals intervals where intervals[i] = [starti, endi] represent the start and the end of the ith interval and intervals is sorted in ascending order by starti. You are also given an interval newInterval = [start, end] that represents the start and end of another interval.
Insert newInterval into intervals such that intervals is still sorted in ascending order by starti and intervals still does not have any overlapping intervals (merge overlapping intervals if necessary).
Return intervalsafter the insertion.
Example 1:
Input: intervals = [[1,3],[6,9]], newInterval = [2,5]
Output: [[1,5],[6,9]]
Example 2:
Input: intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]
Output: [[1,2],[3,10],[12,16]]
Explanation: Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10].
Constraints:
0 <= intervals.length <= 10^4intervals[i].length == 20 <= start_i <= endi <= 10^5intervalsis sorted bystart_iin ascending order.newInterval.length == 20 <= start <= end <= 10^5
Approach 1: One Pass
- C++
- Java
- Python
- Rust
- JavaScript
class Solution {
public:
vector<vector<int>> insert(vector<vector<int>>& intervals, vector<int>& newInterval) {
vector<vector<int>> ans;
int n = intervals.size();
for (int i = 0; i < n; i++) {
if (intervals[i][1] < newInterval[0]) {
// current interval starts first & not covered by newInterval, add intervals[i] to ans
// [curInterval]
// [newInterval]
ans.push_back(intervals[i]);
} else if (intervals[i][0] > newInterval[1]) {
// newInterval starts first and not covered by current interval
// add newInterval to ans and set newInterval = curInterval
// [curInterval]
// [newInterval]
ans.push_back(newInterval);
newInterval = intervals[i];
} else if (intervals[i][1] >= newInterval[0] || intervals[i][0] <= newInterval[1]) {
// they are overlapped, merge them
// [curInterval]
// [newInterval]
// or
// [newInterval]
// [curInterval]
newInterval[0] = min(newInterval[0], intervals[i][0]);
newInterval[1] = max(newInterval[1], intervals[i][1]);
}
}
// add the last interval
ans.push_back(newInterval);
return ans;
}
};
class Solution {
public int[][] insert(int[][] intervals, int[] newInterval) {
List<int[]> ans = new ArrayList<>();
int n = intervals.length;
for (int i = 0; i < n; i++) {
int[] curInterval = intervals[i];
if (intervals[i][1] < newInterval[0]) {
// current interval starts first & not covered by newInterval, add intervals[i] to ans
// [curInterval]
// [newInterval]
ans.add(intervals[i]);
} else if (intervals[i][0] > newInterval[1]) {
// newInterval starts first and not covered by current interval
// add newInterval to ans and set newInterval = curInterval
// [curInterval]
// [newInterval]
ans.add(newInterval);
newInterval = intervals[i];
} else if (intervals[i][1] >= newInterval[0] || intervals[i][0] <= newInterval[1]) {
// they are overlapped, merge them
// [curInterval]
// [newInterval]
// or
// [newInterval]
// [curInterval]
newInterval[0] = Math.min(newInterval[0], intervals[i][0]);
newInterval[1] = Math.max(newInterval[1], intervals[i][1]);
}
}
// add the last interval
ans.add(newInterval);
return ans.toArray(new int[ans.size()][]);
}
}
class Solution:
def insert(self, intervals: List[List[int]], newInterval: List[int]) -> List[List[int]]:
ans = []
n = len(intervals)
for i in range(n):
if intervals[i][1] < newInterval[0]:
# current interval starts first & not covered by newInterval, add intervals[i] to ans
# [curInterval]
# [newInterval]
ans.append(intervals[i])
elif intervals[i][0] > newInterval[1]:
# newInterval starts first and not covered by current interval
# Add newInterval to ans and set newInterval = curInterval
# [curInterval]
# [newInterval]
ans.append(newInterval)
newInterval = intervals[i]
elif intervals[i][1] >= newInterval[0] or intervals[i][0] <= newInterval[1]:
# They are overlapped, merge them
# [curInterval]
# [newInterval]
# or
# [newInterval]
# [curInterval]
newInterval[0] = min(newInterval[0], intervals[i][0])
newInterval[1] = max(newInterval[1], intervals[i][1])
# add the last interval
ans.append(newInterval)
return ans
use std::cmp::min;
use std::cmp::max;
impl Solution {
pub fn insert(intervals: Vec<Vec<i32>>, new_interval: Vec<i32>) -> Vec<Vec<i32>> {
let mut ans = vec![];
let n = intervals.len();
let mut new_interval = new_interval;
for i in 0 .. n {
if intervals[i][1] < new_interval[0] {
// current interval starts first & not covered by newInterval, add intervals[i] to ans
// [curInterval]
// [newInterval]
ans.push(intervals[i].clone());
} else if intervals[i][0] > new_interval[1] {
// NewInterval starts first and not covered by current interval
// Add newInterval to ans and set newInterval = curInterval
// [curInterval]
// [newInterval]
ans.push(new_interval.clone());
new_interval = intervals[i].clone();
} else if intervals[i][1] >= new_interval[0] || intervals[i][0] <= new_interval[1] {
// they are overlapped, merge them
// [curInterval]
// [newInterval]
// or
// [newInterval]
// [curInterval]
new_interval[0] = min(new_interval[0], intervals[i][0]);
new_interval[1] = max(new_interval[1], intervals[i][1]);
}
}
// add the last interval
ans.push(new_interval.clone());
ans
}
}
/**
* @param {number[][]} intervals
* @param {number[]} newInterval
* @return {number[][]}
*/
var insert = function (intervals, newInterval) {
let res = [];
for (i = 0; i < intervals.length; i++) {
if (newInterval[1] < intervals[i][0]) {
res.push(newInterval);
return res.concat(intervals.slice(i, intervals.length));
} else if (newInterval[0] > intervals[i][1]) {
res.push(intervals[i]);
} else {
newInterval[0] = [Math.min(newInterval[0], intervals[i][0])];
newInterval[1] = [Math.max(newInterval[1], intervals[i][1])];
}
}
res.push(newInterval);
return res;
};