{"id":35086,"date":"2024-11-01T09:35:22","date_gmt":"2024-11-01T09:35:22","guid":{"rendered":"http:\/\/atmokpo.com\/w\/?p=35086"},"modified":"2024-11-01T12:45:30","modified_gmt":"2024-11-01T12:45:30","slug":"%ec%bd%94%ed%8b%80%eb%a6%b0-%ec%bd%94%eb%94%a9%ed%85%8c%ec%8a%a4%ed%8a%b8-%ea%b0%95%ec%a2%8c-%ec%99%b8%ed%8c%90%ec%9b%90%ec%9d%98-%ec%88%9c%ed%9a%8c-%ea%b2%bd%eb%a1%9c-%ec%a7%9c%ea%b8%b0-2","status":"publish","type":"post","link":"https:\/\/atmokpo.com\/w\/35086\/","title":{"rendered":"Kotlin coding test course, designing the traveling salesman tour"},"content":{"rendered":"

<\/p>\n

Hello, in this lecture we will learn how to solve the Traveling Salesman Problem using Kotlin.<\/p>\n

1. Problem Definition<\/h2>\n

The Traveling Salesman Problem is the problem of finding the shortest possible route that visits each city once and returns to the original city. The input consists of the travel costs between cities, and the goal is to output a route that visits all cities at the minimum cost.<\/p>\n

2. Problem Approach<\/h2>\n

The Traveling Salesman Problem is known to be NP-hard. Common solutions include brute force, dynamic programming, binary search, and greedy algorithms. However, in special cases dealing with small datasets, it can be solved using brute force.<\/p>\n

The approach to solving this problem is as follows:<\/p>\n

    \n
  1. Represent the distances or costs between all cities in a table format.<\/li>\n
  2. Generate all possible routes.<\/li>\n
  3. Calculate the total cost of each route to find the minimum value.<\/li>\n<\/ol>\n

    3. Kotlin Code for Problem Solving<\/h2>\n

    Now let’s write a code to solve this problem using Kotlin. The code below demonstrates a basic approach to solving the Traveling Salesman Problem:<\/p>\n

    \nfun main() {\n    val n = 4 \/\/ Number of cities\n    val cost = arrayOf(\n        intArrayOf(0, 10, 15, 20),\n        intArrayOf(10, 0, 35, 25),\n        intArrayOf(15, 35, 0, 30),\n        intArrayOf(20, 25, 30, 0)\n    )\n\n    val visited = BooleanArray(n)\n    visited[0] = true \/\/ Set the starting point to the first city\n    val result = tsp(0, 1, cost, visited, 0, n)\n    println(\"Minimum cost is: $result\")\n}\n\nfun tsp(current: Int, count: Int, cost: Array, visited: BooleanArray, totalCost: Int, n: Int): Int {\n    if (count == n) {\n        return totalCost + cost[current][0] \/\/ Return to the starting city after visiting all cities\n    }\n\n    var minCost = Int.MAX_VALUE\n    \n    for (i in 0 until n) {\n        if (!visited[i]) { \/\/ If the city has not been visited\n            visited[i] = true \/\/ Mark city as visited\n            val newCost = tsp(i, count + 1, cost, visited, totalCost + cost[current][i], n)\n            minCost = Math.min(minCost, newCost) \/\/ Calculate minimum cost\n            visited[i] = false \/\/ Backtracking\n        }\n    }\n    \n    return minCost\n}\n<\/intarray><\/code><\/pre>\n
    4. Code Explanation<\/h2>\n
    The above code uses a simple recursive approach to solve the Traveling Salesman Problem. The structure of each function is as follows:<\/p>\n