ソフトウェアエンジニアの技術ブログ：Software engineer tech blog

fn main() {

   let Q = [
      100, 200, 250, 300, 360
   ];

   let R = [
      401, 302, 101, 102, 301
   ];

   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 = Q.len();

   while a > 0 {
      let mut i = 0;
      while i < n {
         if a < Q[i] {
            println!("整理番号{}番の方は{}会場です。", a, R[i]);
            i = n;
         } else {
            i += 1;
         }

      }
   }
}

整理番号100番の方は302会場です。

### 選択ソート

fn main() {

   let A = [
      84, 121, 43, 93, 140, 83, 14, 93, 181, 58
   ];

   let n = A.len();
   seq_sort(n, A);
}

fn seq_sort(n: usize, mut A: [i32; 10]) {
   let mut i = 0;
   let mut B: [i32; 10] = [0; 10];
   let mut k;
   for i in 0..n {
      
      let mut a = 999;
      let mut j = 0;
      for j in j..n {
         if a > A[j] {
            a = A[j];
            k = j;
         }
      }
      A[k] = 999;
      B[i] = a;
   }
   
}

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`
300
1

一つ一つ順番に見ていく

fn main() {

   let cd: [i32; 5] = [10, 2, 94, 34, 2];

   let n: i32 = cd.len() as i32;

   let a = 34;

   let mut i:i32 = 0;
   let mut p:i32 = -1;
   while (i < n && p == -1) {
      if a == cd[i as usize]{
         p = i;
      } else {
         i +=1;
      }
   }
   if p != -1 {
      println!("{}番目にありました", p + 1);
   }
   
}

4番目にありました

fn main() {

   let mut s: [i32; 101] = [1; 101];

   let mut i = 2;
   while i <= 100 {
      s[i] = 1;
      i += 1;
   }

   i = 2;
   while i * i <= 100 {
      let mut j = 2;

      while i * j <= 100 && s[i]!= 0 {
         s[i*j] = 0;
         j += 1;
      }
      i += 1;
   }

   i = 2;
   while i < 100 {
      if s[i] == 1 {
         println!("{}", i);
      }
      i += 1;
   }
}

2
3
5
7
11
13
17
19
23
29
31
37
41
43
47
53
59
61
67
71
73
79
83
89
97

紀元前の話

fn main() {

   let mut s: [i32; 100] = [0; 100];

   let mut i = 1;
   s[0] = 2;

   let mut n = 3;
   let mut j = 0;
   while n <= 100 {
      let quotient = n / s[j];
      let reminder = n % s[j];

      if reminder == 0 {
         n = n + 2;
         j = 1;
      } else {
         if quotient >= s[j] {
            j += 1;
         } else {
            s[j] = n;
            i += 1;
            j = 1;
            n = n + 2;
         }
      }
   }

   let mut i = 0;
   while s[i] != 0 {
      println!("{}", s[i]);
      i += 1;
   }
}

Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.40s
Running `target/debug/basic`
thread ‘main’ panicked at src/main.rs:11:22:
attempt to divide by zero
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

整数を”0″で割るとundefinedでエラーになる。。。
うーん　どう表現したら良いんやろうか

配列の個数がわかっている場合、[[i32; 5]; 6]というような書き方をする。
わかっていない場合はvectorにすれば良い。

fn main() {

   let score:[[i32; 5]; 6] = [
      [65, 71, 74, 82, 97],
      [84, 83, 73, 64, 65],
      [74, 74, 78, 80, 78],
      [90, 90, 90, 90, 90],
      [87, 78, 85, 60, 88],
      [93, 95, 94, 92, 95],
   ];
   println!("番号 国語 数学 理科 社会 英語 合計 平均");

   let mut i = 0;
   while i < 5 {
      let (mut t, mut j) = (0, 0);
      print!("{} ", i);
      while (j <= 4) {
         print!("{} ", score[i][j]);
         t = t + score[i][j];
         j += 1;
      }

      let av = t / j as i32;
      println!("{} {}", t, av);
      i += 1;
   }
}

番号 国語 数学 理科 社会 英語 合計 平均
0 65 71 74 82 97 389 77
1 84 83 73 64 65 369 73
2 74 74 78 80 78 384 76
3 90 90 90 90 90 450 90
4 87 78 85 60 88 398 79

なるほどー

fn main() {

   let mut a;
   let raikyaku: [i32; 7] = [521, 195, 221, 329, 352, 399, 450];

   let mut x = String::new();
   std::io::stdin().read_line(&mut x).expect("Failed to read line");
   let y  = x.trim_end().to_owned();
   a = y.parse::<usize>().unwrap();
   while a != 9 {
      if (a < 0 || a > 6) {
         println!("error");
      } else {
         println!("{}人", raikyaku[a]);
      }
      let mut x = String::new();
      std::io::stdin().read_line(&mut x).expect("Failed to read line");
      x = x.trim_end().to_owned();
      a = x.parse::<usize>().unwrap();
   }
}

fn main() {

   let raikyaku: [i32; 7] = [521, 195, 221, 329, 352, 399, 450];
   let (mut t, mut i) = (0, 0);

   while i < 7 {
      t = t + raikyaku[i];
      i += 1;
   }

   let av = t / i as i32;
   println!("合計: {}", t);
   println!("平均: {}", av);
}

合計: 2467
平均: 352