Learning about vectors

This commit is contained in:
Nidhal Messaoudi 2023-02-27 21:16:40 +01:00
parent f7678b4a9e
commit e3a20b8bc8
5 changed files with 9 additions and 19 deletions

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@ -1,12 +1,10 @@
// move_semantics1.rs
// Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(vec0);
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);

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@ -2,12 +2,10 @@
// Make me compile without changing line 13 or moving line 10!
// Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec0 = Vec::new();
let mut vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(&mut vec0);
// Do not change the following line!
println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
@ -17,12 +15,12 @@ fn main() {
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
fn fill_vec(vec: &mut Vec<i32>) -> Vec<i32> {
let mut vec = vec;
vec.push(22);
vec.push(44);
vec.push(66);
vec
vec.to_vec()
}

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@ -3,8 +3,6 @@
// (no lines with multiple semicolons necessary!)
// Execute `rustlings hint move_semantics3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
@ -17,7 +15,7 @@ fn main() {
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
vec.push(22);
vec.push(44);
vec.push(66);

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@ -4,11 +4,9 @@
// Make me compile and pass the test!
// Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn array_and_vec() -> ([i32; 4], Vec<i32>) {
let a = [10, 20, 30, 40]; // a plain array
let v = // TODO: declare your vector here with the macro for vectors
let v = vec![10, 20, 30, 40]; // TODO: declare your vector here with the macro for vectors
(a, v)
}

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@ -6,13 +6,11 @@
//
// Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
for i in v.iter_mut() {
// TODO: Fill this up so that each element in the Vec `v` is
// multiplied by 2.
???
*i *= 2;
}
// At this point, `v` should be equal to [4, 8, 12, 16, 20].
@ -23,7 +21,7 @@ fn vec_map(v: &Vec<i32>) -> Vec<i32> {
v.iter().map(|num| {
// TODO: Do the same thing as above - but instead of mutating the
// Vec, you can just return the new number!
???
num * 2
}).collect()
}