1. Two Sum #

题目 #

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example:


Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1]

代码 #

use std::collections::HashMap;

impl Solution {
    pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
        let mut numbers: HashMap<i32, i32> = HashMap::new();

        for (idx, value) in nums.iter().enumerate() {
            match numbers.get(&(target - value)) {
                Some(pre_idx) => {
                    return vec![i32::from(*pre_idx), idx as i32];
                },
                None => {
                    numbers.insert(i32::from(*value), idx as i32);
                }
            }
        }

        return vec![];
    }
}