#include <stdlib.h>
//#include <stdio.h>
int *compress_array(const int *input, int n, int *out_size){

    if (input == NULL) return NULL;
    
    int taille = 1;
    for (int i = 0; i < n -1; i++) if(input[i] != input[i + 1]) taille ++;

    *out_size = taille * 2;
   

    int *rslt = malloc(*out_size * sizeof(int));
    if (rslt == NULL) return NULL;


    int index_rslt = 0;
    int index = 0;
    while(index < n){

        int ch_cons = 0;
        int chiffre = input[index];

        while (index < n && input[index] == chiffre){
            ch_cons ++;
            index ++;
        }

        rslt[index_rslt ++] = chiffre;
        rslt[index_rslt ++] = ch_cons;

    }

    return rslt;
    
}
/*
int main(){

        int test[] = {3, 3, 3, 1, 1, 5, 5, 5, 5};
        int sortie = 6;
        int *rs = compress_array(test, 9, &sortie);

        for(int i = 0; i < sortie; i++){
            printf("%i;", rs[i]);
        }
        free(rs);

}*/