Initial commit

solutions/05_vecs/vecs2.rs

@@ -0,0 +1,55 @@
+fn vec_loop(input: &[i32]) -> Vec<i32> {
+    let mut output = Vec::new();
+
+    for element in input {
+        output.push(2 * element);
+    }
+
+    output
+}
+
+fn vec_map_example(input: &[i32]) -> Vec<i32> {
+    // An example of collecting a vector after mapping.
+    // We map each element of the `input` slice to its value plus 1.
+    // If the input is `[1, 2, 3]`, the output is `[2, 3, 4]`.
+    input.iter().map(|element| element + 1).collect()
+}
+
+fn vec_map(input: &[i32]) -> Vec<i32> {
+    // We will dive deeper into iterators, but for now, this is all what you
+    // had to do!
+    // Advanced note: This method is more efficient because it automatically
+    // preallocates enough capacity. This can be done manually in `vec_loop`
+    // using `Vec::with_capacity(input.len())` instead of `Vec::new()`.
+    input.iter().map(|element| 2 * element).collect()
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_vec_loop() {
+        let input = [2, 4, 6, 8, 10];
+        let ans = vec_loop(&input);
+        assert_eq!(ans, [4, 8, 12, 16, 20]);
+    }
+
+    #[test]
+    fn test_vec_map_example() {
+        let input = [1, 2, 3];
+        let ans = vec_map_example(&input);
+        assert_eq!(ans, [2, 3, 4]);
+    }
+
+    #[test]
+    fn test_vec_map() {
+        let input = [2, 4, 6, 8, 10];
+        let ans = vec_map(&input);
+        assert_eq!(ans, [4, 8, 12, 16, 20]);
+    }
+}