C Binary Search implementation code for recursion and non-recursion

Copy codeThe Code is 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 [] = {, 22, 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, if the node to be searched is located in the lower layer, the subscript will be returned for this layer and the flag will be used to catch it...
Flag = binSearch (arr, low, mid-1, key); // I almost forgot to use 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;
}
} // After the above loop ends, it is not necessarily start> ends because of the break statement.
If (start> ends ){
Mid =-1;
}
Return mid;
}