TheAlgorithms-C/leetcode/src/1207.c

#define MAP_SIZE 2048

int cmpvalue(const void *a, const void *b) {
    return *(int *)b - *(int *)a;
}
bool uniqueOccurrences(int* arr, int arrSize){
    int *map = calloc(MAP_SIZE, sizeof(int));
    int i;
    for(i = 0; i < arrSize; i++) {
        if (arr[i] < 0)
            map[arr[i] + MAP_SIZE/2] += 1;
        else
            map[arr[i]] += 1;
    }
    /* number of occurrences is sorted by decreasing order
       Ex: 3 2 1 0 0 0 0 */
    qsort(map, MAP_SIZE, sizeof(int), cmpvalue);
    i = 0;
    while(map[i]) {
        if(map[i] == map[i+1])
            return 0;
        i++;
    }
    return 1;
}