Counting Specific Digits in C Programming

To count the number of specified digits, you can achieve this by either traversing through the array or the digits themselves. Below are examples of both methods.

Option: Method 1: Count the number of specific numbers in the array.

#include <stdio.h>

int countNumber(int arr[], int size, int target) {
    int count = 0;
    
    for (int i = 0; i < size; i++) {
        if (arr[i] == target) {
            count++;
        }
    }
    
    return count;
}

int main() {
    int arr[] = {1, 2, 3, 2, 4, 2, 5};
    int target = 2;
    
    int count = countNumber(arr, 7, target);
    
    printf("数字 %d 在数组中出现的次数为：%d\n", target, count);
    
    return 0;
}

Option two: Count the number of specified digits.

#include <stdio.h>

int countDigit(int num, int target) {
    int count = 0;
    
    while (num > 0) {
        if (num % 10 == target) {
            count++;
        }
        
        num /= 10;
    }
    
    return count;
}

int main() {
    int num = 123452;
    int target = 2;
    
    int count = countDigit(num, target);
    
    printf("数字 %d 在 %d 中出现的次数为：%d\n", target, num, count);
    
    return 0;
}

The code example above can calculate the number of a specified number in an array and in a specified integer. You can choose an appropriate method to count the specified number as needed.