计算数字中特定数字出现的次数

给定数字N和数字D ，任务是计算D在N中的出现次数。

例子：

Input: N = 25, D = 2
Output: 1

Input: N = 100, D = 0
Output: 2

方法：将N中的数字一一取出，并检查该数字是否等于D。如果相等，则将计数加1。最后，打印计数。

下面是上述方法的实现：

C++

// C++ program to count the number of occurrences
// of a particular digit in a number
  
#include 
using namespace std;
  
// Function to count the occurrences
// of the digit D in N
long long int countOccurrances(long long int n,
                               int d)
{
    long long int count = 0;
  
    // Loop to find the digits of N
    while (n > 0) {
  
        // check if the digit is D
        count = (n % 10 == d)
                    ? count + 1
                    : count;
        n = n / 10;
    }
  
    // return the count of the
    // occurrences of D in N
    return count;
}
  
// Driver code
int main()
{
  
    int d = 2;
    long long int n = 214215421;
  
    cout << countOccurrances(n, d)
         << endl;
  
    return 0;
}

Java

// Java program to count the number of occurrences
// of a particular digit in a number
import java.util.*;
  
class GFG
{
  
// Function to count the occurrences
// of the digit D in N
static int countOccurrances(int n,
                            int d)
{
    int count = 0;
  
    // Loop to find the digits of N
    while (n > 0) 
    {
  
        // check if the digit is D
        count = (n % 10 == d) ? 
                    count + 1 : count;
        n = n / 10;
    }
  
    // return the count of the
    // occurrences of D in N
    return count;
}
  
// Driver code
public static void main(String args[])
{
    int d = 2;
    int n = 214215421;
  
    System.out.println(countOccurrances(n, d));
}
}
  
// This code is contributed by Surendra_Gangwar

Python3

# Python3 program to count the 
# number of occurrences of a 
# particular digit in a number
  
# Function to count the occurrences
# of the digit D in N
def countOccurrances(n, d):
    count = 0
  
    # Loop to find the digits of N
    while (n > 0):
  
        # check if the digit is D
        if(n % 10 == d):
            count = count + 1
   
        n = n // 10
  
    # return the count of the
    # occurrences of D in N
    return count
  
# Driver code
d = 2
n = 214215421
print(countOccurrances(n, d))
  
# This code is contributed by Mohit Kumar

C#

// C# program to count the number 
// of occurrences of a particular
// digit in a number
using System;
class GFG
{
  
// Function to count the occurrences
// of the digit D in N
static int countOccurrances(int n,
                            int d)
{
    int count = 0;
  
    // Loop to find the digits of N
    while (n > 0) 
    {
  
        // check if the digit is D
        count = (n % 10 == d) ? 
                    count + 1 : count;
        n = n / 10;
    }
  
    // return the count of the
    // occurrences of D in N
    return count;
}
  
// Driver code
public static void Main()
{
    int d = 2;
    int n = 214215421;
  
    Console.WriteLine(countOccurrances(n, d));
}
}
  
// This code is contributed by Code_Mech.

输出：

3