cake1190



package work;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class Cake1190 {
 static int N, M;
 static int mins;
 static int[] vmin;
 static int[] smin;
 public static void main(String[] args) throws FileNotFoundException {
  /* Scanner sc=new Scanner(System.in); */
  Scanner sc = new Scanner(new File("src/cake1190.txt"));
  mins = 0xfffffff;
  vmin = new int[21];
  smin = new int[21];
  for (int i = 1; i < 21; i++) {
   vmin[i] = vmin[i - 1] + i * i * i;
  }
  for (int i = 1; i < 21; i++) {
   smin[i] = smin[i - 1] + 2 * i * i;
  }
   N = sc.nextInt();// 体积
   M = sc.nextInt();// 层数
   dfs(M, 100, 10000, N, 0);
   if (mins == 0xfffffff){
    System.out.println(0);
   }
   else
    System.out.println(mins);
 }
 // 当前层数，最后一个的半径，最后一个的高，剩下的体积，当前的总表面积
 private static void dfs(int step, int lastr, int lasth, int leftv, int curs) {
  if (step == 0) {
   if (leftv == 0 && mins > curs){
    mins = curs;
   }
   return;
  }
  if (leftv < 0 || leftv <vmin[step]
    || curs + smin[step] >= mins
    || 2 * leftv / lastr + curs >=mins) {
   return;
  }
  for (int r = lastr; r >= step; r--) {
   if (step == M ) {
    curs = r * r;
   }
   for (int h = lasth ; h >= step; h--) {
    dfs(step - 1, r-1, h-1, leftv -h * r * r, curs + 2 * r * h);
   }
  }
  return;
 }
}

、、input

10000
2
100
2

、、output

1424