int main(void){
int key = 0;
int list[10] = {1, 3,4,5,6,7,8,9,12, 20};
int size = ((int)sizeof(list)/ sizeof(int));
int pos;
printList(list ,size);
//test1
key=3;
pos=recursiveBinarySearch(list, 0, size-1, key);
showResult(pos, key);
//test2
key=20;
pos=recursiveBinarySearch(list, 0, size-1, key);
showResult(pos,key);
//test3
key=10;
pos=recursiveBinarySearch(list, 0, size-1, key);
showResult(pos,key);
//test4
key=-1;
pos=recursiveBinarySearch(list, 0, size-1, key);
showResult(pos,key);
//test5
int list1[1]={2};
key=1;
pos=recursiveBinarySearch(list1, 0, 0, key);
showResult(pos,key);
//test6
int list2[2]={1,3};
key=1;
pos=recursiveBinarySearch(list2, 0, 1, key);
showResult(pos,key);
//test7
key=3;
pos=recursiveBinarySearch(list, 0, 1, key);
showResult(pos,key);
//test8
key=0;
pos=recursiveBinarySearch(list, 0, 1, key);
showResult(pos,key);
//test9
key=4;
pos=recursiveBinarySearch(list, 0, 1, key);
showResult(pos,key);
//test10
key=2;
pos=recursiveBinarySearch(list, 0, 1, key);
showResult(pos,key);
return 0;
}
/*
* Part of Cosmos by OpenGenus Foundation
*/
int recursiveBinarySearch(int arr[], int l, int r, int x)
{
if (r >= l)
{
int mid = l + (r - l)/2;
if (arr[mid] == x)
return mid;
if (arr[mid] > x)
return recursiveBinarySearch(arr, l, mid-1, x);
return recursiveBinarySearch(arr, mid+1, r, x);
}
return -1;
}
int main(void)
{
int arr[] = {1, 2, 3, 5};
int size = sizeof(arr)/ sizeof(arr[0]);
int find = 3;
printf("Position of %d is %d\n", find, recursiveBinarySearch(arr, 0, size-1, find));
printf("Position of %d is %d\n", find, binarySearch(arr, 0, size-1, find));
return 0;
}
int recursiveBinarySearch(int list_of_numbers[], int desired_number, int low_number, int high_number) {
int mid = (low_number + high_number) / 2;
if (low_number > high_number)
{
return -1;
}
else if (list_of_numbers[mid] == desired_number)
{
return mid;
}
else if (list_of_numbers[mid] < desired_number)
{
return recursiveBinarySearch(list_of_numbers, desired_number, mid + 1, high_number);
}
else
{
return recursiveBinarySearch(list_of_numbers, desired_number, low_number, mid - 1);
}
}
int recursiveBinarySearch(int list[], int left, int right, int key){
int middle;
if(left>right) return -1;
else{
middle = left + (right - left)/2;
if(key == list[middle]) return middle;
else if(key <list[middle])
right = middle -1;
else
left = middle +1;
return recursiveBinarySearch(list, left, right, key);
}
return -1;
}
int readInput(FILE *input_file, char file_name[], int values[], int desired_number) {
int count = 0;
int value = 0;
int array_size;
input_file = fopen(file_name, "r");
if (feof(input_file) != 0)
{
printf("Error: can't open file\n");
return -1;
}
else
{
printf("File opened successfully\n");
}
//Get the first line of the file, which gives the size of the array
while (fscanf(input_file, "%d", &value) != EOF) {
if (count == 0)//The first value is being read
{
array_size = value - 1;//So that the later ones start at the correct index
}
else {
values[count - 1] = value;
}
count++;
}
fclose(input_file);
int delta;
clock_t t1, t2;
t1 = clock();
int recursive_result = recursiveBinarySearch(values, desired_number, 0, array_size);
t2 = clock();
delta = t2 - t1;
int delta1;
clock_t t3, t4;
t3 = clock();
int iterative_result = iterativeBinarySearch(values, desired_number, array_size);
t4 = clock();
delta1 = t3 - t4;
displayOutput(values, array_size, recursive_result, delta, delta1, iterative_result);
return 0;
}
