sample code for https://paiza.jp/poh/kirishima with awk over Java.

POHLite-kirishima-awk.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;

public class Main {
  public static void main(String[] args) throws Exception {
    StringBuilder script = new StringBuilder();

    script.append("BEGIN {");
    script.append("  FS = \" \";");
    script.append("  requiedNumOfMember  = 0;");
    script.append("  numOfCompany  = 0;");
    script.append("}");
    
    script.append("NF == 1 {");
    script.append("  if(requiedNumOfMember  == 0){");
    script.append("    requiedNumOfMember  = $1");
    script.append("  } else {");
    script.append("    numOfCompany  = $1");
    script.append("  }");
    script.append("}");
    
    script.append("NF == 2 {");
    script.append("  membersOfCompany[FNR - 3] = $1;");
    script.append("  costOfCompany[FNR - 3] = $2;");
    script.append("  numOfMemberIfUseAll += $1;");
    script.append("}");
    
    script.append("END {");
    script.append("  leastCostByNumOfMember[0] = 0;");
    script.append("  for (i = 1; i < numOfMemberIfUseAll + 1 ; i++) {");
    script.append("    leastCostByNumOfMember[i] = -1;");
    script.append("  }");
    script.append("  for (i = 0; i < numOfCompany; i++) {");
    script.append("    for (j = numOfMemberIfUseAll; j >= membersOfCompany[i]; j--) {");
    script.append("      costWithoutCompanyJ = leastCostByNumOfMember[j - membersOfCompany[i]];");
    script.append("      if (costWithoutCompanyJ >= 0) {");
    script.append("        newCost = costWithoutCompanyJ + costOfCompany[i];");
    script.append("        if (leastCostByNumOfMember[j] < 0 || leastCostByNumOfMember[j] > newCost) {");
    script.append("          leastCostByNumOfMember[j] = newCost;");
    script.append("        }");
    script.append("      }");
    script.append("    }");
    script.append("  }");
    script.append("  j = -1;");
    script.append("  for (i = requiedNumOfMember; i <= numOfMemberIfUseAll; i++) {");
    script.append("    if (j < 0 || (leastCostByNumOfMember[i] >= 0 && j > leastCostByNumOfMember[i])) {");
    script.append("      j = leastCostByNumOfMember[i];");
    script.append("    }");
    script.append("  }");
    script.append("  print j;");
    script.append("}");

    ProcessBuilder pb = new ProcessBuilder("/bin/sh", "-c", "awk '" + script.toString() + "'");
    pb.redirectErrorStream(true);
    Process process = pb.start();
    passInputToOutput(System.in, process.getOutputStream());
    process.waitFor();
    printInputStream(process.getInputStream());
    process.waitFor();
  }

  static void passInputToOutput(InputStream in, OutputStream out) throws IOException {
    byte[] buffer = new byte[1024];
    int len = in.read(buffer);
    while (len != -1) {
      out.write(buffer, 0, len);
      len = in.read(buffer);
    }
    out.close();
  }


  static void printInputStream(InputStream is) throws IOException {
    try (BufferedReader br = new BufferedReader(new InputStreamReader(is))) {
      while (true) {
        String line = br.readLine();
        if (line == null)
          break;
        System.out.println(line);
      }
    }
  }
}