完整示例

struct Solution;
impl Solution {
    pub fn two_sum(nums:Vec<i32>,target:i32)->Vec<i32> {
        use std::collections::HashMap;
        let mut map:HashMap<i32, i32> = HashMap::new();
        for (i,&num) in nums.iter().enumerate() {
            let complement = target - num;
            if let Some(&j)=map.get(&complement) {
                return vec![j,i as i32];
            }
            map.insert(num, i as i32);
        }
        vec![]
    }
}
fn main() {
    let nums = vec![2, 7, 11, 15];
    let target = 9;
    let result = Solution::two_sum(nums, target);
    println!("{:?}", result);
}

分析

依赖

• use std::collections::HashMap;

创建哈希表 插入键值对 获取值 更新值 遍历

let map = HashMap::new(); //创建
map.insert("K",13); //(k,v)
map.get("K"); // ->13 返回值13
map.insert("K",11); //更新值
for(k,v)in &map{  //遍历

}