C Two-point lookup recursive and non-recursive implementation code _c language

Copy Code code as follows:

#include <stdio.h>

int binsearch (int arr[], int low, int high, int key);
int binSearch2 (int arr[], int low, int high, int key);
int BinSearch3 (int arr[],int start,int ends,int key);
int main () {
int arr[]={3,8,11,15,17,22,23,26,28,29,34};
printf ("%d", Binsearch (arr,0,10,26));
printf ("%d", BinSearch3 (arr,0,10,26));
return 1;
}

int binsearch (int arr[], int low, int high, int key) {
int flag=-1;
int mid = (low + high)/2;
if (Low > High) {
flag=-1;
} else {

if (Arr[mid] < key) {
Flag= Binsearch (arr, mid + 1, high, key);
else if (Arr[mid]>key) {
For example, to find the node at the bottom of this layer then this layer will return to the subscript to catch with flag ...
flag= Binsearch (Arr,low,mid-1,key)//And almost forgot to use the flag to catch the return value

} else {
Flag= mid;
}
}
return flag;
}

ok==============================
int binSearch2 (int arr[], int low, int high, int key) {
int mid = (low + high)/2;
if (Low > High) {
return-1;
} else {

if (Arr[mid] < key) {
Return BinSearch2 (arr, mid + 1, high, key);
else if (Arr[mid]>key) {
Return BinSearch2 (Arr,low,mid-1,key);
} else {
return mid;
}
}

}

int BinSearch3 (int arr[],int start,int ends,int key) {
int mid=-1;
while (Start<=ends) {
Mid= (start+ends)/2;
if (Arr[mid]<key) {
start=mid+1;
}else if (arr[mid]>key) {
Ends=mid-1;
}else{
Break
}
}//the above loops are not necessarily start>ends because there are break statements
if (start>ends) {
Mid=-1;
}
return mid;
}