#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int find(int * keys, int target, int len){
  int high = len;
  int low = -1;

  int probe;
  while (high - low > 1){
    //printf("low: %d high: %d\n", low, high);
    probe = (low + high) >> 1;
    if (keys[probe] > target) {
      high = probe;
    } else {
      low = probe;
    }
  }
  if (low == -1 || keys[low] != target) {
    return -1;
  } else {
    return low;
  }
}

int find2(int * keys, int target, int len){
  int high = len;
  int low = -1;

  int probe;
  while (high - low > 1){
    //printf("low: %d high: %d\n", low, high);
    probe = (low + high) >> 1;
    if (keys[probe] == target) { return probe;} 
    if (keys[probe] > target) {
      high = probe;
    } else {
      low = probe;
    }
  }
  if (low == -1 || keys[low] != target) {
    return -1;
  } else {
    return low;
  }
}


int main(int argc, char ** argv){

  int max = 1000000;
  int array[max];
  int spread = 1;

  array[0] = 0;
  int inc;
  for (int i = 1; i < max; i++) {
    inc = rand() % spread;
    inc = (inc > 0) ? inc : -inc;
    array[i] = array[i] + 1 + inc;
  }


  int k;
  int result;
  for (int j = 1; j < argc; j++){
    result = (rand()) % (2*max);
    result = (result < 0) ? -result : result;

    k = find(array, result, max);
    printf("%d %s found.\n", result, (k == -1) ? " NOT " : " is ");
    k = find2(array, result, max);
    printf("%d %s found(2).\n", result, (k == -1) ? " NOT " : " is ");

  }

  clock_t t;
  double time_taken;
  int reps = 10000000;
  printf("spread: %d\n", spread);
  t = clock();
  printf("%d finds:", reps);
  for (int i = 0; i < reps; i++){
    result = (rand()) % (2*max);
    result = (result < 0) ? -result : result;
    k = find(array, result, max);
  }
  t = clock() - t;
  time_taken = ((double) t)/CLOCKS_PER_SEC;
  printf("done. Time: %f\n", time_taken);

  t = clock();
  printf("%d find(2)s:", reps);
  for (int i = 0; i < reps; i++){
    result = (rand()) % (2*max);
    result = (result < 0) ? -result : result;
    k = find2(array, result, max);
  }
  t = clock() - t;
  time_taken = ((double) t)/CLOCKS_PER_SEC;
  printf("done. Time: %f\n", time_taken);


  return (0);
}