4020. Elevator Requests I

You are given an integer n denoting the number of floors in a building, where the floors are numbered from 0 to n - 1.

You are also given an integer array requests, where requests represents the sequence of floor requests.

An elevator starts at floor 0 and follows these rules:

• The elevator moves one floor per second.
• The elevator serves requests in the given order.
• If the elevator is already on the requested floor, no movement is needed.
• After serving a request, the elevator immediately starts moving toward the next request.

Return the total time in seconds required to serve all requests.

class Solution {
public:
    int elevatorRequests(int n, vector<int>& requests) {
        int res = 0, at = 0;
        for(int x : requests) {
            res += abs(at - x);
            at = x;
        }
        return res;
    }
};