1.两数之和

https://leetcode-cn.com/problems/two-sum/

func twoSum(_ nums: [Int], _ target: Int) -> [Int] {
    var resultDic = Dictionary<Int, Int>()
    for (index, item) in nums.enumerated() {
        let  minusValue = target - item
        if resultDic.keys.contains(minusValue) {
            return [resultDic[minusValue]!, index]
        }
        resultDic.updateValue(index, forKey: item);
    }
    print(resultDic)
    return []
}