【Rust】バイナリーサーチ【アルゴリズム】

fn main() {

   let mut commodity: [String; 8] = [
      "ジュース".to_string(),
      "紅茶".to_string(),
      "アイスティ".to_string(),
      "コーヒー".to_string(),
      "アイスコーヒー".to_string(),
      "ショートケーキ".to_string(),
      "チーズケーキ".to_string(),
      "トースト".to_string(),
   ];

   let mut price: [i32; 8] = [
      280, 300, 320, 350, 370, 550, 600, 650
   ];

   let mut x = String::new();
   std::io::stdin().read_line(&mut x).expect("Failed to read line");
   let x  = x.trim_end().to_owned();
   let a = x.parse::<i32>().unwrap();

   let n = commodity.len() as i32;
   bin_search(a, n, price);
   // seq_search();
}

fn bin_search(a: i32, n: i32, price: [i32; 8]) {
   let mut p = -1;
   let mut l = 0;
   let mut h = n - 1;

   while (l <= h && p == -1) {
      if (a > price[((l+h) / 2) as usize]) {
         l = (l + h) / 2 + 1;
      } else {
         if (a == price[((l+h)/2) as usize]) {
            p = (l +h) / 2;
         } else {
            h = (l + h) / 2 - 1;
         }
      }
   }
   println!("{}", p);
}

Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
Running `target/debug/basic`
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