public static void countSort(List<List<String>> arr) {
        int middle = arr.size() / 2;
        int temp[] = new int[100];
        
        Map<Integer, List<String>> map = new HashMap<>();
        
        // Traverse the list and populate hashmap
        // with keys being the "weight" of the pair.
        // Also replace the str to "-" if it is between [0..n/2].
        for(int i = 0; i < arr.size(); i++) {
            
            List<String> a = arr.get(i);
            int weight = Integer.parseInt(a.get(0));
            String str = a.get(1);
            
            if(i < middle) {
                str = "-";
            }
            
            temp[weight]++;
            
            if(map.containsKey(weight)) {
                map.get(weight).add(str);
            } else {
                map.put(weight, new ArrayList<String>());
                map.get(weight).add(str);
            }
        }
        
        // The base of count sort adapted to 
        // this challenge.
        for(int i = 0; i < temp.length; i++) {
            
            int repeat = temp[i];
            
            for (int j = 0; j < repeat; j++) {
                System.out.print(map.get(i).get(j) + " ");
            }
        }
        
    }

def countSort(arr):
    # Write your code here
    # the number of element in the array_res is max(arr[:,0]) + 1
    length_arr_res = 0
    for i in arr:
        if int(i[0]) > int(length_arr_res):
            length_arr_res = int(i[0])
    arr_res = [[] for i in range(length_arr_res+1)]
    # find first half array and convert it to '-'.
    for i in range(len(arr)//2):
        arr_res[int(arr[i][0])].append('-')
    # add last half array
    for i in range(len(arr)//2,len(arr)):
        arr_res[int(arr[i][0])].append(arr[i][1])
    # print it out
    for i in arr_res:
        for j in i:
            print(j,end=' ')

function countSort(arr) {
  // Write your code here
  const obj = {};
  const mid = arr.length / 2;
  arr.forEach((e, i) => {
    if (i < mid) {
      if (obj[e[0]]) obj[e[0]].push('-');
      else obj[e[0]] = ['-']
      return
    }
    if (obj[e[0]]) obj[e[0]].push(e[1])
    else obj[e[0]] = [e[1]]
  })

  console.log(Object.values(obj).map((e) => e.join(' ')).join(' '));
}

void countSort(int arr_rows, int arr_columns, char*** arr) {
    int i;
    int range[100] = {0};
    int new_range[100] = {0};
    char ** res = (char**)malloc(sizeof(char) * 10 * arr_rows);
    
    
    // step 0: replace first half with '-'
    for (i = 0; i < arr_rows / 2; i++)
        strcpy(arr[i][1], "-");
    
    
    // step 1: populating range
    for (i = 0; i < arr_rows; i++){
        int num = atoi(arr[i][0]);
        range[num]++;
    }
    // step 2: inctremting range
    for (i = 1; i < 100; i++)
        range[i] += range[i - 1];
    // step 3: shifting range array by 1
    for (i = 1; i < 100; i++)
        new_range[i] = range[i - 1];
    
    // step 4: sort
    for (i = 0; i < arr_rows; i++){
        int num = atoi(arr[i][0]);
        int r_i = new_range[num];
        res[r_i] = arr[i][1];
        new_range[num]++;
    }
    
    // step 5: print sorting result
    for (i = 0; i < arr_rows; i++)
        printf("%s ", res[i]);
    
    free(res);
    printf("\n");
    
}