# 2678. Number of Senior Citizens

## Description

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] is either 'M' or 'F' or 'O'.
• The phone numbers and seat numbers of the passengers are distinct.

## Solutions

• class Solution {
public int countSeniors(String[] details) {
int ans = 0;
for (var x : details) {
int age = Integer.parseInt(x.substring(11, 13));
if (age > 60) {
++ans;
}
}
return ans;
}
}

• class Solution {
public:
int countSeniors(vector<string>& details) {
int ans = 0;
for (auto& x : details) {
int age = stoi(x.substr(11, 2));
ans += age > 60;
}
return ans;
}
};

• class Solution:
def countSeniors(self, details: List[str]) -> int:
return sum(int(x[11:13]) > 60 for x in details)


• func countSeniors(details []string) (ans int) {
for _, x := range details {
age, _ := strconv.Atoi(x[11:13])
if age > 60 {
ans++
}
}
return
}

• impl Solution {
pub fn count_seniors(details: Vec<String>) -> i32 {
let mut ans = 0;

for s in details.iter() {
if let Ok(age) = s[11..13].parse::<i32>() {
if age > 60 {
ans += 1;
}
}
}

ans
}
}

• function countSeniors(details: string[]): number {
let ans = 0;
for (const x of details) {
const age = parseInt(x.slice(11, 13));
if (age > 60) {
++ans;
}
}
return ans;
}