Question

How to count all duplicate elements in int array using C

Answer 1

#include <stdio.h>
  
int main(int argc, char **argv) 
{
	int arr[] = { 1, 1, 2, 3, 4, 4, 4, 5, 6, 6, 7, 7, 7, 7 };
    int duplicate[10] = {0};
    int len = sizeof(arr) / sizeof(arr[0]);
     
    for (int i = 0; i < len; i++) {
        for (int j = 0; j < len; j++) {
            if (arr[i] == arr[j]) {
                duplicate[arr[i]]++;
                break;
            }
        }
    }
     
    for (int i = 0; i < 10; i++) {
        if (duplicate[i] > 1)
            printf("%d : %d\n", i, duplicate[i]);
    }
 
    return 0; 
}
   
     
/*
run:
   
1 : 2
4 : 3
6 : 2
7 : 4

*/

 

70+ SQL courses for beginners and professionals