875. 爱吃香蕉的珂珂

/**

• @author: 施龙青

• @description 875. 爱吃香蕉的珂珂

• @date: 2022/6/7 1:24
  */
  public class Main001 {
  //测试
  public static void main(String[] args) {
  Main001 main001 = new Main001();
  int[] a = new int[]{30, 11, 23, 4, 20};
  System.out.println(main001.minEatingSpeed(a, 5));
  }

  public int minEatingSpeed(int[] piles, int h) {
  int len = piles.length;

   //二分的是速度，从1开始，到最大香蕉数
   int left = 1;
   int right = -1;
   for (int pile : piles) {
       if (right < pile) {
           right = pile;
       }
   }
   while (left < right) {
       int mid = (right - left) / 2 + left;
       if (calculateSum(piles, mid) > h) {
           left = mid + 1;
       } else {
           right = mid;
       }
   }
   return left;
  

  }

  int calculateSum(int[] piles, int speed) {
  int sum = 0;

   for (int pile : piles) {
       //向上取整
       sum += (pile + speed - 1) / speed;
   }
   return sum;
  

  }
  }