#include "stdio.h"
#include "stdlib.h"
#include "string.h"

int compare(const void* a, const void* b) {
  return (*(int*)a - *(int*)b);
}

int main(int argc, char* argv[]) {
  int size = 0;
  int lines = 0;
  int sum = 0;
  int* list1 = NULL;
  int* list2 = NULL;

  if(argc < 2) {
    fprintf(stderr, "Filename required\n");
    return 1;
  }

  FILE* file = fopen(argv[1], "r");
  if(file == NULL) {
    fprintf(stderr, "Could not open %s\n", argv[1]);
    return 2;
  }

  char* line = NULL;
  size_t line_size = 0;
  while(getline(&line, &line_size, file) > 0) {
    lines += 1;
  }

  rewind(file);
  list1 = malloc(sizeof(int)*lines);
  list2 = malloc(sizeof(int)*lines);

  for(int i = 0; i < lines; i++) {
    char* line_save = NULL;
    getline(&line, &line_size, file);
    char* num1 = strtok_r(line, " ", &line_save);
    char* num2 = strtok_r(NULL, " ", &line_save);
    if(num1 == NULL || num2 == NULL) continue;

    list1[i] = atoi(num1);
    list2[i] = atoi(num2);
    size += 1;
  }
  free(line);

  qsort(list1, size, sizeof(int), compare);
  qsort(list2, size, sizeof(int), compare);

  for(int i = 0; i < size; i++) {
    sum += abs(list1[i] - list2[i]);
  }

  fprintf(stdout, "Sum: %d\n", sum);

  int similarity = 0;
  int* counts = malloc(sizeof(int)*size);
  memset(counts, 0, sizeof(int)*size);

  for(int i = 0; i < size; i++) {
    for(int j = 0; j < size; j++) {
      if(list1[i] == list2[j]) counts[i] += 1;
    }
  }

  for(int i = 0; i < size; i++){
    similarity += list1[i] * counts[i];
  }

  fprintf(stdout, "Similarity: %d\n", similarity);

  return 0;
}