Question

1058. Minimize Rounding Error to Meet Target

中文文档

Description

Given an array of prices [p1,p2...,pn] and a target, round each price pi to Roundi(pi) so that the rounded array [Round1(p1),Round2(p2)...,Roundn(pn)] sums to the given target. Each operation Roundi(pi) could be either Floor(pi) or Ceil(pi).

Return the string "-1" if the rounded array is impossible to sum to target. Otherwise, return the smallest rounding error, which is defined as Σ |Roundi(pi) - (pi)| forifrom 1 ton, as a string with three places after the decimal.

 

Example 1:

Input: prices = ["0.700","2.800","4.900"], target = 8
Output: "1.000"
Explanation:
Use Floor, Ceil and Ceil operations to get (0.7 - 0) + (3 - 2.8) + (5 - 4.9) = 0.7 + 0.2 + 0.1 = 1.0 .

Example 2:

Input: prices = ["1.500","2.500","3.500"], target = 10
Output: "-1"
Explanation: It is impossible to meet the target.

Example 3:

Input: prices = ["1.500","2.500","3.500"], target = 9
Output: "1.500"

 

Constraints:

• 1 <= prices.length <= 500
• Each string prices[i] represents a real number in the range [0.0, 1000.0] and has exactly 3 decimal places.
• 0 <= target <= 106

Solutions

Solution 1

class Solution:
  def minimizeError(self, prices: List[str], target: int) -> str:
    mi = 0
    arr = []
    for p in prices:
      p = float(p)
      mi += int(p)
      if d := p - int(p):
        arr.append(d)
    if not mi <= target <= mi + len(arr):
      return "-1"
    d = target - mi
    arr.sort(reverse=True)
    ans = d - sum(arr[:d]) + sum(arr[d:])
    return f'{ans:.3f}'

class Solution {
  public String minimizeError(String[] prices, int target) {
    int mi = 0;
    List<Double> arr = new ArrayList<>();
    for (String p : prices) {
      double price = Double.valueOf(p);
      mi += (int) price;
      double d = price - (int) price;
      if (d > 0) {
        arr.add(d);
      }
    }
    if (target < mi || target > mi + arr.size()) {
      return "-1";
    }
    int d = target - mi;
    arr.sort(Collections.reverseOrder());
    double ans = d;
    for (int i = 0; i < d; ++i) {
      ans -= arr.get(i);
    }
    for (int i = d; i < arr.size(); ++i) {
      ans += arr.get(i);
    }
    DecimalFormat df = new DecimalFormat("#0.000");
    return df.format(ans);
  }
}

class Solution {
public:
  string minimizeError(vector<string>& prices, int target) {
    int mi = 0;
    vector<double> arr;
    for (auto& p : prices) {
      double price = stod(p);
      mi += (int) price;
      double d = price - (int) price;
      if (d > 0) {
        arr.push_back(d);
      }
    }
    if (target < mi || target > mi + arr.size()) {
      return "-1";
    }
    int d = target - mi;
    sort(arr.rbegin(), arr.rend());
    double ans = d;
    for (int i = 0; i < d; ++i) {
      ans -= arr[i];
    }
    for (int i = d; i < arr.size(); ++i) {
      ans += arr[i];
    }
    string s = to_string(ans);
    return s.substr(0, s.find('.') + 4);
  }
};

func minimizeError(prices []string, target int) string {
  arr := []float64{}
  mi := 0
  for _, p := range prices {
    price, _ := strconv.ParseFloat(p, 64)
    mi += int(math.Floor(price))
    d := price - float64(math.Floor(price))
    if d > 0 {
      arr = append(arr, d)
    }
  }
  if target < mi || target > mi+len(arr) {
    return "-1"
  }
  d := target - mi
  sort.Float64s(arr)
  ans := float64(d)
  for i := 0; i < d; i++ {
    ans -= arr[len(arr)-i-1]
  }
  for i := d; i < len(arr); i++ {
    ans += arr[len(arr)-i-1]
  }
  return fmt.Sprintf("%.3f", ans)
}