2678. Number of Senior Citizens LeetCode Solution

In this guide, you will get 2678. Number of Senior Citizens LeetCode Solution with the best time and space complexity. The solution to Number of Senior Citizens 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 Senior Citizens solution in C++
  4. Number of Senior Citizens solution in Java
  5. Number of Senior Citizens solution in Python
  6. Additional Resources
2678. Number of Senior Citizens LeetCode Solution image

Problem Statement of Number of Senior Citizens

You are given a 0-indexed array of strings details. Each element of details provides information about a given passenger compressed into a string of length 15. The system is such that:

The first ten characters consist of the phone number of passengers.
The next character denotes the gender of the person.
The following two characters are used to indicate the age of the person.
The last two characters determine the seat allotted to that person.

Return the number of passengers who are strictly more than 60 years old.

Example 1:

Input: details = [“7868190130M7522″,”5303914400F9211″,”9273338290F4010”]
Output: 2
Explanation: The passengers at indices 0, 1, and 2 have ages 75, 92, and 40. Thus, there are 2 people who are over 60 years old.

Example 2:

Input: details = [“1313579440F2036″,”2921522980M5644”]
Output: 0
Explanation: None of the passengers are older than 60.

Constraints:

1 <= details.length <= 100
details[i].length == 15
details[i] consists of digits from '0' to '9'.
details[i][10] is either 'M' or 'F' or 'O'.
The phone numbers and seat numbers of the passengers are distinct.

See also  2588. Count the Number of Beautiful Subarrays LeetCode Solution

Complexity Analysis

  • Time Complexity: O(n)
  • Space Complexity: O(1)

2678. Number of Senior Citizens LeetCode Solution in C++

class Solution {
 public:
  int countSeniors(vector<string>& details) {
    return ranges::count_if(details, [](const string& detail) {
      return stoi(detail.substr(11, 2)) > 60;
    });
  }
};
/* code provided by PROGIEZ */

2678. Number of Senior Citizens LeetCode Solution in Java

class Solution {
  public int countSeniors(String[] details) {
    return (int) Arrays.stream(details)
        .filter(detail -> Integer.parseInt(detail.substring(11, 13)) > 60)
        .count();
  }
}
// code provided by PROGIEZ

2678. Number of Senior Citizens LeetCode Solution in Python

class Solution:
  def countSeniors(self, details: list[str]) -> int:
    return sum(int(detail[11:13]) > 60 for detail in details)
 # code by PROGIEZ

Additional Resources

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