2251. Number of Flowers in Full Bloom LeetCode Solution

In this guide, you will get 2251. Number of Flowers in Full Bloom LeetCode Solution with the best time and space complexity. The solution to Number of Flowers in Full Bloom problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Table of Contents

1. Problem Statement
2. Complexity Analysis
3. Number of Flowers in Full Bloom solution in C++
4. Number of Flowers in Full Bloom solution in Java
5. Number of Flowers in Full Bloom solution in Python
6. Additional Resources

Problem Statement of Number of Flowers in Full Bloom

You are given a 0-indexed 2D integer array flowers, where flowers[i] = [starti, endi] means the ith flower will be in full bloom from starti to endi (inclusive). You are also given a 0-indexed integer array people of size n, where people[i] is the time that the ith person will arrive to see the flowers.
Return an integer array answer of size n, where answer[i] is the number of flowers that are in full bloom when the ith person arrives.

Example 1:

Input: flowers = [[1,6],[3,7],[9,12],[4,13]], people = [2,3,7,11]
Output: [1,2,2,2]
Explanation: The figure above shows the times when the flowers are in full bloom and when the people arrive.
For each person, we return the number of flowers in full bloom during their arrival.

Example 2:

Input: flowers = [[1,10],[3,3]], people = [3,3,2]
Output: [2,2,1]
Explanation: The figure above shows the times when the flowers are in full bloom and when the people arrive.
For each person, we return the number of flowers in full bloom during their arrival.

Constraints:

1 <= flowers.length <= 5 * 104
flowers[i].length == 2
1 <= starti <= endi <= 109
1 <= people.length <= 5 * 104
1 <= people[i] <= 109

Complexity Analysis

• Time Complexity: O(\texttt{sort} + |\texttt{persons}|\log n)
• Space Complexity: O(n + |\texttt{persons}|)

2251. Number of Flowers in Full Bloom LeetCode Solution in C++

class Solution {
 public:
  vector<int> fullBloomFlowers(vector<vector<int>>& flowers,
                               vector<int>& persons) {
    vector<int> ans;
    vector<int> starts;
    vector<int> ends;

    for (const vector<int>& flower : flowers) {
      starts.push_back(flower[0]);
      ends.push_back(flower[1]);
    }

    ranges::sort(starts);
    ranges::sort(ends);

    for (const int p : persons) {
      const int started = ranges::upper_bound(starts, p) - starts.begin();
      const int ended = ranges::lower_bound(ends, p) - ends.begin();
      ans.push_back(started - ended);
    }

    return ans;
  }
};
/* code provided by PROGIEZ */

2251. Number of Flowers in Full Bloom LeetCode Solution in Java

class Solution {
  public int[] fullBloomFlowers(int[][] flowers, int[] persons) {
    int[] ans = new int[persons.length];
    List<Integer> starts = new ArrayList<>();
    List<Integer> ends = new ArrayList<>();

    for (int[] flower : flowers) {
      starts.add(flower[0]);
      ends.add(flower[1]);
    }

    Collections.sort(starts);
    Collections.sort(ends);

    for (int i = 0; i < persons.length; ++i) {
      final int started = firstGreater(starts, persons[i]);
      final int ended = firstGreaterEqual(ends, persons[i]);
      ans[i] = started - ended;
    }

    return ans;
  }

  private int firstGreater(List<Integer> A, int target) {
    int l = 0;
    int r = A.size();
    while (l < r) {
      final int m = (l + r) / 2;
      if (A.get(m) > target)
        r = m;
      else
        l = m + 1;
    }
    return l;
  }

  private int firstGreaterEqual(List<Integer> A, int target) {
    int l = 0;
    int r = A.size();
    while (l < r) {
      final int m = (l + r) / 2;
      if (A.get(m) >= target)
        r = m;
      else
        l = m + 1;
    }
    return l;
  }
}
// code provided by PROGIEZ

2251. Number of Flowers in Full Bloom LeetCode Solution in Python

class Solution:
  def fullBloomFlowers(
      self,
      flowers: list[list[int]],
      persons: list[int],
  ) -> list[int]:
    starts = sorted(s for s, _ in flowers)
    ends = sorted(e for _, e in flowers)
    return [bisect.bisect_right(starts, person) -
            bisect.bisect_left(ends, person)
            for person in persons]
 # code by PROGIEZ

Additional Resources

• Explore all LeetCode problem solutions at Progiez here
• Explore all problems on LeetCode website here

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