sample code for https://paiza.jp/poh/kirishima

POHLite-kirishima-nashone.java

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

public class Main {

  public static void main(String[] args) throws ScriptException {
    int requiedNumOfMember = 0;
    int numOfCompany = 0;
    int numOfMemberIfUseAll = 0;
    List<Integer> membersOfCompany = new ArrayList<>();
    List<Integer> costOfCompany = new ArrayList<>();
    // 入力データの読み込み。
    try (Scanner scanner = new Scanner(System.in)) {
      requiedNumOfMember = scanner.nextInt();
      numOfCompany = scanner.nextInt();
      for (int i = 0; i < numOfCompany; i++) {
        membersOfCompany.add(scanner.nextInt());
        numOfMemberIfUseAll += membersOfCompany.get(i);
        costOfCompany.add(scanner.nextInt());
      }
    };
    ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");

    String script
      = "var requiedNumOfMember = " + requiedNumOfMember + ";\n"
      + "var numOfCompany = " + numOfCompany + ";\n"
      + "var numOfMemberIfUseAll = " + numOfMemberIfUseAll + ";\n"
      + "var membersOfCompany = " + membersOfCompany + ";\n"
      + "var costOfCompany = " + costOfCompany + ";\n"
      + "var leastCostByNumOfMember = []; \n"
      + "// 先頭以外を未処理　(-1)で初期化\n"
      + "leastCostByNumOfMember[0] = 0\n"
      + "for (var i = 0; i < numOfMemberIfUseAll; i++) {\n"
      + "  leastCostByNumOfMember[leastCostByNumOfMember.length] = -1;\n"
      + "}\n"
      + "for (var i = 0; i < numOfCompany; i++) {\n"
      + "  // i 番目の会社の処理\n"
      + "  for (var j = numOfMemberIfUseAll; j >= membersOfCompany[i]; j--) {\n"
      + "    // 全人数　から、この会社の人数まで順に処理。\n"
      + "    // leastCostByNumOfMember[j]に対してi 番目の会社を使うとより安くなるなら更新\n"
      + "    var costWithoutCompanyJ = leastCostByNumOfMember[j - membersOfCompany[i]];\n"
      + "    if (costWithoutCompanyJ >= 0) {\n"
      + "      var newCost = costWithoutCompanyJ + costOfCompany[i];\n"
      + "      if (leastCostByNumOfMember[j] < 0 || leastCostByNumOfMember[j] > newCost) {\n"
      + "        //未設定あるいはより安くなるなら更新\n"
      + "        leastCostByNumOfMember[j] = newCost;\n"
      + "      }\n"
      + "    }\n"
      + "  }\n"
      + "}\n"
      + "var j = -1;\n"
      + "for (var i = requiedNumOfMember; i <= numOfMemberIfUseAll; i++) {\n"
      + "  if (j < 0 || (leastCostByNumOfMember[i] >= 0 && j > leastCostByNumOfMember[i])) {\n"
      + "    j = leastCostByNumOfMember[i];\n"
      + "  }\n"
      + "}\n"
      + "print(j);\n";
    engine.eval(script);
  }
}