50 lines
1.2 KiB
Rust
50 lines
1.2 KiB
Rust
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// TODO: implement a multi-threaded version of the `sum` function
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// using `spawn` and `join`.
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// Given a vector of integers, split the vector into two halves and
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// sum each half in a separate thread.
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// Caveat: We can't test *how* the function is implemented,
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// we can only verify that it produces the correct result.
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// You _could_ pass this test by just returning `v.iter().sum()`,
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// but that would defeat the purpose of the exercise.
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//
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// Hint: you won't be able to get the spawn threads to _borrow_
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// slices of the vector directly. You'll need to allocate new
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// vectors for each half of the original vector. We'll see why
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// this is necessary in the next exercise.
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use std::thread;
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pub fn sum(v: Vec<i32>) -> i32 {
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todo!()
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn empty() {
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assert_eq!(sum(vec![]), 0);
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}
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#[test]
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fn one() {
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assert_eq!(sum(vec![1]), 1);
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}
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#[test]
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fn five() {
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assert_eq!(sum(vec![1, 2, 3, 4, 5]), 15);
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}
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#[test]
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fn nine() {
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assert_eq!(sum(vec![1, 2, 3, 4, 5, 6, 7, 8, 9]), 45);
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}
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#[test]
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fn ten() {
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assert_eq!(sum(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]), 55);
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}
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}
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