feat: add solution for coin change in rust

Author: bujosa

src/medium/coin_change.rs

@@ -0,0 +1,28 @@
+#![allow(dead_code)]
+pub fn coin_change(coins: Vec<i32>, amount: i32) -> i32 {
+    let mut dp = vec![amount + 1; (amount + 1) as usize];
+    dp[0] = 0;
+
+    for a in 1..=amount {
+        for &c in &coins {
+            if c <= a {
+                dp[a as usize] = dp[a as usize].min(dp[(a - c) as usize] + 1);
+            }
+        }
+    }
+
+    if dp[amount as usize] > amount {
+        -1
+    } else {
+        dp[amount as usize]
+    }
+}
+
+#[test]
+fn test_coin_change() {
+    assert_eq!(coin_change(vec![1, 2, 5], 11), 3);
+    assert_eq!(coin_change(vec![2], 3), -1);
+    assert_eq!(coin_change(vec![1], 0), 0);
+    assert_eq!(coin_change(vec![1], 1), 1);
+    assert_eq!(coin_change(vec![1], 2), 2);
+}

src/readme.md

@@ -88,7 +88,7 @@
   - [x] [238. Product of array except self](../src/medium/product_of_array_except_self.rs) -> [Problem Description](../src/medium/readme.md#238-product-of-array-except-self)
   - [x] [271. Encode and decode strings](../src/medium/encode_and_decode_strings.rs) -> [Problem Description](../src/medium/readme.md#271-encode-and-decode-strings)
   - [x] [287. Find the duplicate number](../src/medium/find_the_duplicate_number.rs) -> [Problem Description](../src/medium/readme.md#287-find-the-duplicate-number)
-  - [ ] [322. Coin change](../src/medium/coin_change.rs) -> [Problem Description](../src/medium/readme.md#322-coin-change)
+  - [x] [322. Coin change](../src/medium/coin_change.rs) -> [Problem Description](../src/medium/readme.md#322-coin-change)
   - [x] [347. Top k frequent elements](../src/medium/top_k_frequent_elements.rs) -> [Problem Description](../src/medium/readme.md#347-top-k-frequent-elements)
   - [x] [355. Design twitter](../src/medium/design_twitter.rs) -> [Problem Description](../src/medium/readme.md#355-design-twitter)
   - [x] [424. Longest repeating character replacement](../src/medium/longest_repeating_character_replacement.rs) -> [Problem Description](../src/medium/readme.md#424-longest-repeating-character-replacement)

theory/categories/6.1d_dp/readme.md

@@ -26,7 +26,7 @@ Dynamic programming and greedy algorithms are similar. Both are optimization met
 - [x] [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/) | Medium | [Solution](../../../src/medium/longest_palindromic_substring.rs) | [Problem Description](../../../src/medium/readme.md#5-longest-palindromic-substring)
 - [x] [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/) | Medium | [Solution](../../../src/medium/palindromic_substrings.rs) | [Problem Description](../../../src/medium/readme.md#647-palindromic-substrings)
 - [x] [Decode Ways](https://leetcode.com/problems/decode-ways/) | Medium | [Solution](../../../src/medium/decode_ways.rs) | [Problem Description](../../../src/medium/readme.md#91-decode-ways)
-- [ ] [Coin Change](https://leetcode.com/problems/coin-change/) | Medium | [Solution](../../../src/medium/coin_change.rs) | [Problem Description](../../../src/medium/readme.md#322-coin-change)
+- [x] [Coin Change](https://leetcode.com/problems/coin-change/) | Medium | [Solution](../../../src/medium/coin_change.rs) | [Problem Description](../../../src/medium/readme.md#322-coin-change)
 - [x] [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/) | Medium | [Solution](../../../src/medium/maximum_product_subarray.rs) | [Problem Description](../../../src/medium/readme.md#152-maximum-product-subarray)
 - [ ] [Word Break](https://leetcode.com/problems/word-break/) | Medium | [Solution](../../../src/medium/word_break.rs) | [Problem Description](../../../src/medium/readme.md#139-word-break)
 - [ ] [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/) | Medium | [Solution](../../../src/medium/longest_increasing_subsequence.rs) | [Problem Description](../../../src/medium/readme.md#300-longest-increasing-subsequence)