Question

如何从整数中删除所有零？如果int只是零，它将返回0，但如果不是，则返回一个相同的整数，除非它没有任何0。

我尝试将其传递给String，然后在删除完成后传递给整数，但它再次带有0。

我该怎么做？

    public static void main(String[] args) {

        // test method removeZeros
        test_removeZeros(0); // result = 0
        test_removeZeros(2); // result = 2
        test_removeZeros(10); // result = 1
        test_removeZeros(101); // result = 11
        test_removeZeros(10050); // result = 15
        test_removeZeros(-30100); // result = -31
        System.out.println();

    }

    private static void test_removeZeros(int n) {

        try {

            System.out.print("removeZeros (" + n + ") = ");
            int res = removeZeros(n);
            System.out.println(res);

        } catch (IllegalArgumentException e) {
            System.out.println("Error: " + e.getMessage());
        }
    }

    private static int removeZeros(int n) {
            int finalresult= n;
            int result;
            String medium;


            if (n == 0){

                result= 0;
                result= finalresult;

            } else{

                medium= Integer.toString(n);        
                int x = Integer.parseInt(medium.substring(0));
                result= Integer.valueOf(medium);
                result= finalresult;

            }

            finalresult = result;
            return finalresult;

        }

Answer 1

Integer.parseInt(Integer.toString(a).replace("0", ""))

上面的单行检查将Int转换为String将所有字符删除为0.然后转换回int。在上面的答案中，a表示int变量。并且您可能需要在执行此操作之前检查if a != 0，因为它会抛出NumberFormatException

 private static int removeZeros(int a) {

     if (a != 0) {

         return Integer.parseInt(Integer.toString(a).replace("0", ""))
     }
     return 0
 }

Answer 2

让我感到沮丧的是，只能使用字符串转换来解决这个问题。这不是必要的，如果你不使用它会更有趣。

相反，您可以递归地解决它：依次遍历每个数字，如果它们非零，则将它们添加到结果中。像这样：

int withoutZeros(int i) {
  return withoutZeros(i, 0, 1);
}

int withoutZeros(int remainingDigits, int result, int mul) {
  // mul is the multiplier to put the last digit in the right place
  // in the result. For instance, if mul is 100, and the last digit
  // of remainingDigits is 4, the final result will end with 4??.

  // There are no more digits; so return the result.
  if (remainingDigits == 0) return result;

  int lastDigit = remainingDigits % 10;

  // The last digit is a zero, so we don't include in the result.
  if (lastDigit == 0) return withoutZeros(i / 10, result, mul);

  // Otherwise, add the last digit of i to the result.
  // We have to multiply by mul in order to put this digit
  // "in the right place" in the result (because this processes
  // the digits in reverse order).
  // Increase mul for the next iteration.
  return withoutZeros(i / 10, result + lastDigit * mul, 10 * mul);
}

Ideone demo

由于这是尾递归的，你可以把它写成循环：

int withoutZeros(int i) {
  int result = 0;
  for (int remainingDigits = i, mul = 1; remainingDigits > 0; remainingDigits /= 10) {
    int lastDigit = remainingDigits % 10;
    if (lastDigit != 0) {
      result += lastDigit * mul;
      mul *= 10;
    }
  }
  return result;
}

Answer 3

您可以尝试这样做：

int intWithZeros = 1020300; // for example
String intAsString = String.valueOf(intWithZeros); // represent the int as a String
String resultString= "";
for (char digit : intAsString.toCharArray()) { // cycle through every char 
    if(digit!='0') { // if it is not a zero
     resultString+=digit; // append it to the resultString
    }
}
if (!resultString.equals("")) {
    return Integer.parseInt(resultString);
}
return 0;

<强>输入：

<强>输出：

如何从整数中删除零？

3 个答案: