Merge pull request #251 from xBLACKICEx/rust-computational_complexity

Rust computational complexity

codes/rust/.gitignore

@@ -0,0 +1,3 @@
+**/target
+**/worst_best_time_complexity/
+**/time_complexity/

codes/rust/Cargo.lock

@@ -0,0 +1,75 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "chapter_computational_complexity"
+version = "0.1.0"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c05aeb6a22b8f62540c194aac980f2115af067bfe15a0734d7277a768d396b31"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.139"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "201de327520df007757c1f0adce6e827fe8562fbc28bfd9c15571c66ca1f5f79"
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"

codes/rust/Cargo.toml

@@ -0,0 +1,5 @@
+
+[workspace]
+members = [
+    "chapter_computational_complexity",
+]

codes/rust/chapter_computational_complexity/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "chapter_computational_complexity"
+version = "0.1.0"
+edition = "2021"
+
+
+[[bin]]
+name = "leetcode_two_sum"
+path = "leetcode_two_sum.rs"
+
+[[bin]]
+name = "time_complexity"
+path = "time_complexity.rs"
+
+[[bin]]
+name = "worst_best_time_complexity"
+path = "worst_best_time_complexity.rs"
+
+
+[dependencies]
+rand = "0.8.5"

codes/rust/chapter_computational_complexity/leetcode_two_sum.rs

@@ -0,0 +1,50 @@
+/**
+ * File: leetcode_two_sum.rs
+ * Created Time: 2023-01-14
+ * Author: xBLACICEx (xBLACKICEx@outlook.com)
+*/
+
+use std::collections::HashMap;
+struct SolutionBruteForce;
+struct SolutionHashMap;
+
+impl SolutionBruteForce {
+    pub fn two_sum(nums: &Vec<i32>, target: i32) -> Vec<i32> {
+        for i in 0..nums.len() - 1 {
+            for j in i + 1..nums.len() {
+                if nums[i] + nums[j] == target {
+                    return vec![i as i32, j as i32];
+                }
+            }
+        }
+        vec![]
+    }
+}
+
+impl SolutionHashMap {
+    pub fn two_sum(nums: &Vec<i32>, target: i32) -> Vec<i32> {
+        let mut hm = HashMap::new();
+    
+        for (i, n) in nums.iter().enumerate() {
+            match hm.get(&(target - n)) {
+                Some(v) => return vec![*v as i32, i as i32],
+                None => hm.insert(n, i)
+            };
+        }
+        vec![]
+    }
+}
+
+// Driver Code
+fn main() {
+    // ======= Test Case =======
+    let nums = vec![2,7,11,15];
+    let target = 9;
+
+    // 方法一
+    let res = SolutionBruteForce::two_sum(&nums, target);
+    println!("方法一 res = {:?}", res);
+    // 方法二
+    let res = SolutionHashMap::two_sum(&nums, target);
+    println!("方法二 res = {:?}", res);
+}

codes/rust/chapter_computational_complexity/time_complexity.rs

@@ -1,4 +1,9 @@
-#![allow(unused_variables)]
+/**
+ * File: time_complexity.rs
+ * Created Time: 2023-01-10
+ * Author: xBLACICEx (xBLACKICEx@outlook.com)
+*/
+#[allow(unused_variables)]
 
 /* 常数阶 */
 fn constant(n: i32) -> i32 {
@@ -10,6 +15,7 @@ fn constant(n: i32) -> i32 {
     count
 }
 
+/* 线性阶 */
 fn linear(n: i32) -> i32 {
     let mut count = 0;
     for _ in 0..n {
@@ -92,6 +98,7 @@ fn logarithmic(mut n: i32) -> i32 {
     count
 }
 
+/* 对数阶（递归实现） */
 fn log_recur(n: i32) -> i32 {
     if n <= 1 {
         return 0;

codes/rust/chapter_computational_complexity/worst_best_time_complexity.rs

@@ -0,0 +1,38 @@
+/**
+ * File: time_complexity.rs
+ * Created Time: 2023-01-13
+ * Author: xBLACICEx (xBLACKICEx@outlook.com)
+ */
+
+use rand::seq::SliceRandom;
+use rand::thread_rng;
+
+/* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
+fn random_numbers(n: i32) -> Vec<i32> {
+    // 生成数组 nums = { 1, 2, 3, ..., n }
+    let mut nums = (1..n + 1).collect::<Vec<i32>>();
+    // 随机打乱数组元素
+    nums.shuffle(&mut thread_rng());
+    nums
+}
+
+/* 查找数组 nums 中数字 1 所在索引 */
+fn find_one(nums: &[i32]) -> Option<usize> {
+    for i in 0..nums.len() {
+        if nums[i] == 1 {
+            return Some(i);
+        }
+    }
+    None
+}
+
+/* Driver Code */
+fn main() {
+    for _ in 0..10 {
+        let n = 100;
+        let nums = random_numbers(n);
+        let index = find_one(&nums);
+        println!("\n数组 [ 1, 2, ..., n ] 被打乱后 = {:?}", nums);
+        println!("数字 1 的索引为 {:?}", index);
+    }
+}