knapsack - added solution

README.md

@@ -46,7 +46,7 @@ A collection of resources and code snippets for learning rust.
 | 5 | Fizzy | [Link](exercism-solutions/rust/fizzy/src/lib.rs) | ⭐⭐ | ✔️ |
 | 6 | Grep | [Link](exercism-solutions/rust/grep/src/lib.rs) |  | ❌ |
 | 7 | Hamming | [Link](exercism-solutions/rust/hamming/src/lib.rs) | ⭐⭐ | ✔️ |
-| 8 | Knapsack | [Link](exercism-solutions/rust/knapsack/src/lib.rs) |  | ❌ |
+| 8 | Knapsack | [Link](exercism-solutions/rust/knapsack/src/lib.rs) | ⭐⭐ | ✔️ |
 | 9 | Luhn-from | [Link](exercism-solutions/rust/luhn-from/src/lib.rs) | ⭐⭐ | ✔️ |
 | 10 | Luhn-trait | [Link](exercism-solutions/rust/luhn-trait/src/lib.rs) | ⭐⭐ | ✔️ |
 | 11 | Luhn | [Link](exercism-solutions/rust/luhn/src/lib.rs) | ⭐⭐ | ✔️ |

exercism-solutions/rust/knapsack/src/lib.rs

@@ -5,5 +5,24 @@ pub struct Item {
 }
 
 pub fn maximum_value(max_weight: u32, items: &[Item]) -> u32 {
-    todo!("calculate the maximum value achievable with the given {items:?} and {max_weight}");
+    let max_weight_usize = max_weight as usize;
+    let mut values = vec![vec![0; max_weight_usize + 1]; items.len() + 1];
+
+    for item_idx in 1..=items.len() {
+        let item = &items[item_idx - 1];
+        let weight_usize = item.weight as usize;
+        let value_usize = item.value as usize;
+
+        for curr_capacity in 1..=max_weight_usize {
+            let mut curr_value = values[item_idx - 1][curr_capacity];
+            if curr_capacity >= weight_usize {
+                curr_value = curr_value
+                    .max(values[item_idx - 1][curr_capacity - weight_usize] + value_usize);
+            }
+
+            values[item_idx][curr_capacity] = curr_value;
+        }
+    }
+
+    values[items.len()][max_weight_usize] as u32
 }

learning-rust.code-workspace

@@ -44,6 +44,7 @@
 			"./exercism-solutions/rust/macros/Cargo.toml",
 			"./exercism-solutions/rust/custom-set/Cargo.toml",
 			"./exercism-solutions/rust/grep/Cargo.toml",
+			"./exercism-solutions/rust/knapsack/Cargo.toml",
 			"./exercism-solutions/rust/queen-attack/Cargo.toml",
 			"./exercism-solutions/rust/simple-linked-list/Cargo.toml",
 			"./rust-book/book/Cargo.toml",