# Two City Scheduling🦦

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Question

A company is planning to interview `2n` people. Given the array `costs` where `costs[i] = [aCosti, bCosti]`, the cost of flying the `ith` person to city `a` is `aCosti`, and the cost of flying the `ith` person to city `b` is `bCosti`.

Return the minimum cost to fly every person to a city such that exactly `n` people arrive in each city.

Example 1:

`Input: costs = [[10,20],[30,200],[400,50],[30,20]]Output: 110Explanation: The first person goes to city A for a cost of 10.The second person goes to city A for a cost of 30.The third person goes to city B for a cost of 50.The fourth person goes to city B for a cost of 20.The total minimum cost is 10 + 30 + 50 + 20 = 110 to have half the people interviewing in each city.`

Example 2:

`Input: costs = [[259,770],[448,54],[926,667],[184,139],[840,118],[577,469]]Output: 1859`

Example 3:

`Input: costs = [[515,563],[451,713],[537,709],[343,819],[855,779],[457,60],[650,359],[631,42]]Output: 3086`

Constraints:

• `2 * n == costs.length`
• `2 <= costs.length <= 100`
• `costs.length` is even.
• `1 <= aCosti, bCosti <= 1000`

# Solution

Time complexity O(n log n)

Space complexity O(1)