Exercise 2: Sum of Squares - Hints

Hint 1: Using a for loop

The simplest approach uses a for loop:

#![allow(unused)]
fn main() {
let mut sum = 0;
for &num in nums {
    sum += num * num;
}
sum
}

You can use map to square each element, then sum to add them:

#![allow(unused)]
fn main() {
nums.iter().map(|&x| x * x).sum()
}

fold is a general accumulation method:

#![allow(unused)]
fn main() {
nums.iter().fold(0, |acc, &x| acc + x * x)
}

The first argument is the initial value, the closure takes (accumulator, element).