hello-algo/codes/rust/chapter_computational_complexity/leetcode_two_sum.rs

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/**
* File: leetcode_two_sum.rs
* Created Time: 2023-01-14
* Author: xBLACICEx (xBLACKICEx@outlook.com )
*/
use std::collections::HashMap;
struct SolutionBruteForce;
struct SolutionHashMap;
impl SolutionBruteForce {
pub fn two_sum(nums: &Vec<i32>, target: i32) -> Vec<i32> {
for i in 0..nums.len() - 1 {
for j in i + 1..nums.len() {
if nums[i] + nums[j] == target {
return vec![i as i32, j as i32];
}
}
}
vec![]
}
}
impl SolutionHashMap {
pub fn two_sum(nums: &Vec<i32>, target: i32) -> Vec<i32> {
let mut hm = HashMap::new();
for (i, n) in nums.iter().enumerate() {
match hm.get(&(target - n)) {
Some(v) => return vec![*v as i32, i as i32],
None => hm.insert(n, i)
};
}
vec![]
}
}
// Driver Code
fn main() {
// ======= Test Case =======
let nums = vec![2,7,11,15];
let target = 9;
// 方法一
let res = SolutionBruteForce::two_sum(&nums, target);
println!("方法一 res = {:?}", res);
// 方法二
let res = SolutionHashMap::two_sum(&nums, target);
println!("方法二 res = {:?}", res);
}