Package g0801_0900.s0825_friends_of_appropriate_ages

Class Solution

java.lang.Object
g0801_0900.s0825_friends_of_appropriate_ages.Solution
public class Solution extends java.lang.Object
825 - Friends Of Appropriate Ages.

Medium

There are n persons on a social media website. You are given an integer array ages where ages[i] is the age of the ith person.

A Person x will not send a friend request to a person y (x != y) if any of the following conditions is true:

  • age[y] <= 0.5 * age[x] + 7
  • age[y] > age[x]
  • age[y] > 100 && age[x] < 100

Otherwise, x will send a friend request to y.

Note that if x sends a request to y, y will not necessarily send a request to x. Also, a person will not send a friend request to themself.

Return the total number of friend requests made.

Example 1:

Input: ages = [16,16]

Output: 2

Explanation: 2 people friend request each other.

Example 2:

Input: ages = [16,17,18]

Output: 2

Explanation: Friend requests are made 17 -> 16, 18 -> 17.

Example 3:

Input: ages = [20,30,100,110,120]

Output: 3

Explanation: Friend requests are made 110 -> 100, 120 -> 110, 120 -> 100.

Constraints:

  • n == ages.length
  • 1 <= n <= 2 * 104
  • 1 <= ages[i] <= 120

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numFriendRequests(int[] ages)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • numFriendRequests

      public int numFriendRequests(int[] ages)