Two City Schedule - Day 3

Author: suriyakrishna

src/main/scala/com/kishan/scala/leetcode/juneChallenges/twoCityScheduling.scala

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+package com.kishan.scala.leetcode.juneChallenges
+
+/*
+There are 2N people a company is planning to interview. The cost of flying the i-th person to city A is costs[i][0],
+and the cost of flying the i-th person to city B is costs[i][1].
+Return the minimum cost to fly every person to a city such that exactly N people arrive in each city.
+*/
+
+/*
+Input: [[10,20],[30,200],[400,50],[30,20]]
+Output: 110
+Explanation:
+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.
+
+Note:
+  1.  1 <= costs.length <= 100
+  2.  It is guaranteed that costs.length is even.
+  3.  1 <= costs[i][0], costs[i][1] <= 1000
+*/
+  
+/*
+* Approach (Greedy Algorithm)
+* 1. Find absolute difference.
+* 2. Sort in descending order.
+* 3. Iterate and get the minimum of the city. Update the sum.
+* 4. Have the count of the cityA and cityB.
+* */
+
+
+object twoCityScheduling {
+  def main(args: Array[String]): Unit = {
+    val costs = Array(Array(259, 770), Array(448, 54), Array(926, 667), Array(184, 139), Array(840, 118), Array(577, 469))
+    //    val costs1 = Array(Array(10, 20), Array(30, 200), Array(400, 50), Array(30, 20))
+    val result = twoCitySchedCost(costs)
+    println(result, result == 1859)
+  }
+
+  def twoCitySchedCost(costs: Array[Array[Int]]): Int = {
+    val length = costs.length
+    if (length % 2 != 0 && (length <= 1 && length >= 100)) {
+      return -1
+    }
+    val costsSorted: Array[Array[Int]] = costs.map(a => (a, math.abs(a(0) - a(1)))).sortBy(a => a._2)(Ordering.Int.reverse).map(_._1)
+    var cityA: Int = 0
+    var cityB: Int = 0
+    var sum: Int = 0
+    for (person <- costsSorted) {
+      val a = person(0)
+      val b = person(1)
+      if (a < b) {
+        if (cityA < length / 2) {
+          sum += a
+          cityA += 1
+        } else {
+          sum += b
+          cityB += 1
+        }
+      } else {
+        if (cityB < length / 2) {
+          sum += b
+          cityB += 1
+        } else {
+          sum += a
+          cityA += 1
+        }
+      }
+    }
+    sum
+  }
+
+
+}