查找给定数字的中间数字

给定数字N ，任务是找到给定数字N的中间数字。如果数字有两个中间数字，则打印第一个中间数字。
例子：

Input: N = 12345 
Output: 3

Input: N = 98562 
Output: 5  

方法：任何数字N的中间数字可以由

$\left ( \frac{N}{10^{\frac{len}{2}}} \right )\ mod 10$

给定数字的长度( len )可以计算为

$\left ( \log_{10} N \right ) + 1$

例如：

If N = 12345 
len = (int)log₁₀(12345) + 1 = 5 
Therefore, 
First half of N = N/10^5/2 = N/10² = 123 
Therefor middle digit of N = last digit of First half of N = (First half of N) % 10 = 123 % 10 = 3 

下面的代码是上述方法的实现：

C++

// Program to find middle digit of number
 
#include 
using namespace std;
 
// Function to find the middle digit
int middleDigit(int n)
{
    // Find total number of digits
    int digits = (int)log10(n) + 1;
 
    // Find middle digit
    n = (int)(n / pow(10, digits / 2))
        % 10;
 
    // Return middle digit
    return n;
}
 
// Driver program
int main()
{
    // Given Number N
    int N = 98562;
 
    // Function call
    cout << middleDigit(N)
         << "\n";
    return 0;
}

Java

// Java program to find middle digit of number
class GFG{
 
// Function to find the middle digit
static int middleDigit(int n)
{
     
    // Find total number of digits
    int digits = (int)Math.log10(n) + 1;
 
    // Find middle digit
    n = (int)(n / Math.pow(10, digits / 2)) % 10;
 
    // Return middle digit
    return n;
}
 
// Driver Code
public static void main(String[] args)
{
     
    // Given number N
    int N = 98562;
 
    // Function call
    System.out.println(middleDigit(N));
}
}
 
// This code is contributed by rutvik_56

Python3

# Python3 Program to find middle digit of number
import math
 
# Function to find the middle digit
def middleDigit(n):
 
    # Find total number of digits
    digits = math.log10(n) + 1;
 
    # Find middle digit
    n = int((n // math.pow(10, digits // 2))) % 10;
 
    # Return middle digit
    return n;
 
# Driver program
 
# Given Number N
N = 98562;
 
# Function call
print(middleDigit(N))
 
# This code is contributed by Code_Mech

C#

// C# program to find middle digit of number
using System;
 
class GFG{
     
// Function to find the middle digit
static int middleDigit(int n)
{
         
    // Find total number of digits
    int digits = (int)Math.Log10(n) + 1;
     
    // Find middle digit
    n = (int)(n / Math.Pow(10, digits / 2)) % 10;
     
    // Return middle digit
    return n;
}
 
// Driver code
static void Main()
{
         
    // Given number N
    int N = 98562;
     
    // Function call
    Console.WriteLine(middleDigit(N));
}
}
 
// This code is contributed by divyeshrabadiya07

Javascript

// Program to find middle digit of number
 
// Function to find the middle digit
function middleDigit(n)
{
    // Find total number of digits
    let digits = parseInt(Math.log10(n) + 1);
 
    // Find middle digit
    n = parseInt(parseInt(n / Math.pow(10, parseInt(digits / 2))) % 10);
 
    // Return middle digit
    return n;
}
 
// Driver program
// Given Number N
let N = 98562;
 
// Function call
document.write(middleDigit(N));
 
// This code is contributed by subham348.

输出：

5

时间复杂度： O(1)

辅助空间： O(1)