Code shared from the Rust Playground

playground.rs

#![allow(dead_code)]

use std::convert::TryInto;

fn binary_search<'a>(ar:&'a [i32], elem:i32, startIndex:usize, endIndex:usize) -> isize{
  let mid:usize = (startIndex + endIndex)/2;
  let mut res:isize = -1;
  let midelem:i32 = ar[mid];
  
  if startIndex > endIndex {//|| (startIndex == endIndex && midelem != elem) {
      return res;
  }
  println!("start = {}, end ={}, and mid = {},",startIndex, endIndex, mid);
  
  if midelem == elem{
      res =  mid.try_into().unwrap();
  }else if midelem > elem {
      res =  binary_search(ar, elem, startIndex, mid - 1);
  }else{
      res = binary_search(ar, elem, mid + 1, endIndex);
  }
  
  return res;
}
fn main() {
   let a:[i32;5] = [1,2,3,4,5];
   println!("Index of 0 = {}", binary_search(&a, 90, 0, a.len()-1));
   println!("The result is {}", (8/3))
}