Question

How to print array elements that appear more than once in C

Answer 1

#include <stdio.h>
#include <stdlib.h>
  
void printMoreThanOnce(int arr[], int len) {
   int *freq = (int *)calloc(sizeof(int), 10);
     
   for (int i = 0; i < len; i++) {
         freq[arr[i]]++;
   }
     
   for (int i = 0; i < 10; i++) {
      if (freq[i] > 1)
         printf("%3d", i);
   }
     
   free(freq);
}
   
int main() {
    int arr[] = {1, 6, 3, 1, 8, 9, 9, 1, 3, 4};
   
    printMoreThanOnce(arr, sizeof(arr)/sizeof(arr[0]));
}
  
  
  
/*
run:
  
1  3  9
    
*/

 

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