825. Friends Of Appropriate Ages
Description
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
Solutions
Solution 1
1 2 3 4 5 6 7 8 9 10 11 12 13 |
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 |
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 |
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
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