two-sum.rs

use std::collections::HashMap;
impl Solution {
    pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
        let mut lookup = HashMap::new();
        for i in 0..nums.len() {
            let key = &(target- nums[i]);
            if lookup.contains_key(key) {
                return vec![*lookup.get(key).unwrap(), (i as i32)];
            }
            lookup.insert(nums[i], (i as i32));
        }
        return vec![];
    }
}