Classic Interview 150 Questions P57 Insert Interval

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Timeline

Timeline

2025-11-18

init

range

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Problem:

P57 Insert Interval

https://leetcode.cn/problems/insert-interval/description/?envType=study-plan-v2&envId=top-interview-150

First process the ones that cannot be merged, then process the ones that can be merged, and finally process the rest.
For the ones that can be merged:

new_left = std::min(new_left, curr_left);
new_right = std::max(new_right, curr_right);

Code:

#include <vector>
#include <algorithm>
using std::vector;

class Solution {
    public:
	vector<vector<int> > insert(vector<vector<int> > &intervals, vector<int> &newInterval)
	{
		vector<vector<int> > res;
		int i, n = intervals.size();
		int curr_left, curr_right, new_left = newInterval[0], new_right = newInterval[1];

		for (i = 0; i < n; i++) {
			curr_left = intervals[i][0];
			curr_right = intervals[i][1];

			if (curr_right < new_left)
				res.push_back({ curr_left, curr_right });
			else
				break;

		}

		// Merge Intervals
		for (; i < n; i++) {
			curr_left = intervals[i][0];
			curr_right = intervals[i][1];
			if (curr_left <= new_right) {
				new_left = std::min(new_left, curr_left);
				new_right = std::max(new_right, curr_right);

			} else {
				break;
			}
		}

		res.push_back({ new_left, new_right });

		for (; i < n; i++) {
			curr_left = intervals[i][0];
			curr_right = intervals[i][1];
			res.push_back({ curr_left, curr_right });
		}
		return res;
	}
};