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2117. Abbreviating the Product of a Range 👎

  • Time: $O(\texttt{right} - \texttt{left})$
  • Space: $O(1)$
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class Solution {
 public:
  string abbreviateProduct(int left, int right) {
    constexpr long maxSuf = 100'000'000'000;
    double prod = 1.0;
    long suf = 1;
    int countDigits = 0;
    int countZeros = 0;

    for (int num = left; num <= right; ++num) {
      prod *= num;
      while (prod >= 1.0) {
        prod /= 10;
        ++countDigits;
      }
      suf *= num;
      while (suf % 10 == 0) {
        suf /= 10;
        ++countZeros;
      }
      if (suf > maxSuf)
        suf %= maxSuf;
    }

    if (countDigits - countZeros <= 10) {
      const long tens = pow(10, countDigits - countZeros);
      return to_string(static_cast<long>(prod * tens + 0.5)) + 'e' +
             to_string(countZeros);
    }

    const string pre = to_string(static_cast<long>(prod * pow(10, 5)));
    string sufStr = to_string(suf);
    sufStr = sufStr.substr(sufStr.length() - 5);
    return pre + "..." + sufStr + 'e' + to_string(countZeros);
  }
};

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class Solution {
  public String abbreviateProduct(int left, int right) {
    final long maxSuf = 100_000_000_000L;
    double prod = 1.0;
    long suf = 1;
    int countDigits = 0;
    int countZeros = 0;

    for (int num = left; num <= right; ++num) {
      prod *= num;
      while (prod >= 1.0) {
        prod /= 10;
        ++countDigits;
      }
      suf *= num;
      while (suf % 10 == 0) {
        suf /= 10;
        ++countZeros;
      }
      if (suf > maxSuf)
        suf %= maxSuf;
    }

    if (countDigits - countZeros <= 10) {
      final long tens = (long) Math.pow(10, countDigits - countZeros);
      return String.valueOf((long) (prod * tens + 0.5)) + "e" + String.valueOf(countZeros);
    }

    final String pre = String.valueOf((long) (prod * Math.pow(10, 5)));
    String sufStr = String.valueOf(suf);
    sufStr = sufStr.substring(sufStr.length() - 5);
    return pre + "..." + sufStr + "e" + String.valueOf(countZeros);
  }
}

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class Solution:
  def abbreviateProduct(self, left: int, right: int) -> str:
    prod = 1.0
    suf = 1
    countDigits = 0
    countZeros = 0

    for num in range(left, right + 1):
      prod *= num
      while prod >= 1.0:
        prod /= 10
        countDigits += 1
      suf *= num
      while suf % 10 == 0:
        suf //= 10
        countZeros += 1
      if suf > 10**8:
        suf %= 10**8

    if countDigits - countZeros <= 10:
      tens = 10**(countDigits - countZeros)
      return str(int(prod * tens + 0.5)) + 'e' + str(countZeros)

    pre = str(int(prod * 10 ** 5))
    suf = str(suf)[-5:]
    return pre + '...' + suf + 'e' + str(countZeros)