[Java] 數字跟字串轉換

  

int n =1234;

方法一:

 String str1 = Integer.toString(n); 

方法二:

 String str3 = String.valueOf(n);

字串轉成矩陣

  String[] stringarray = str1.split(""); // stringarray =[1,2,3,4]

字串轉成數字

int index1 = Integer.parseInt(stringarray[0]);

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[LeetCode]

1281. Subtract the Product and Sum of Digits of an Integer

Given an integer number n, return the difference between the product of its digits and the sum of its digits.

 

Example 1:

Input: n = 234
Output: 15 
Explanation: 
Product of digits = 2 * 3 * 4 = 24 
Sum of digits = 2 + 3 + 4 = 9 
Result = 24 - 9 = 15

Example 2:

Input: n = 4421
Output: 21
Explanation: 
Product of digits = 4 * 4 * 2 * 1 = 32 
Sum of digits = 4 + 4 + 2 + 1 = 11 
Result = 32 - 11 = 21

 

Constraints:

• 1 <= n <= 10^5

Solution:

class Solution {

    public int subtractProductAndSum(int n) {

        

        String str1 = Integer.toString(n); 

        String str3 = String.valueOf(n); 

        

        String[] stringarray = str1.split("");

        int mul = 1;

        int sum = 0;

        

     

        System.out.println(str3);

        

        

        for(int i =0;i<stringarray.length;i++)

        {

            sum += Integer.parseInt(stringarray[i]);

            mul *= Integer.parseInt(stringarray[i]);

            

        

        }

        

        int result = mul-sum;

        return result;

        

        

      

    }

}