vector<int> twoSum(vector<int>& nums,inttarget) { vector<int>res; unordered_map<int,int>hash;for(inti =0; i < nums.size(); i++) {//记录待查值,接下来搜索intanother = target -nums[i];if(hash.count(another)) {//res记录下标,
classSolution{public:vector<int>twoSum(vector<int>& nums,inttarget){ unordered_map<int,int> hashtable;for(inti =0; i < nums.size(); ++i) {autoit = hashtable.find(target - nums[i]);if(it != hashtable.end()) {return{it->second, i}; } hashtable[nums[i]] = i; }return{};...
用法 1. 简介 map和unordered_map都是c++中可以充当(key-value)来用的数据类型,但是基本实现是不一样的。 2. map 对于map的底层原理,是通过红黑树(一种非严格意义上的平衡二叉树)来实现的,因此内部所有的数据都是有序的,map的查询、插入、删除操作的时间复杂度都是O(logn)。此外,map的key需要定义...
问如何在C++ 11及更高版本中以std::vector的形式手动发布std::map和std::unordered_map资源ENstd::as...
2、其次就是准备C++语言,我也是在b站上看看黑马的教学视频反正,后面接着就是查漏补缺,经常看看拓跋阿秀的笔记,复习复习,C++中的STL库很重要,像这个vector,map, set,unordered_map等经常被问道其中vector最常问,如如何避免扩容等等。这个我是看的STL源码解析上面的内容的还是很不错的。C++语言的常问多态怎么实现的...
unordered_map<string, vector<string>>letters{//声母--韵母 组合{"B",{"a","o","i","u","ai","ei","ao","iao","ie","an","ian","en","in","ang","eng","ing"}}, {"P",{"a","o","i","u","ai","ei","ao","iao","ou","ie","an","ian","en","in","ang","...
unordered_map<string, vector<string>>letters{//声母--韵母 组合{"B",{"a","o","i","u","ai","ei","ao","iao","ie","an","ian","en","in","ang","eng","ing"}}, {"P",{"a","o","i","u","ai","ei","ao","iao","ou","ie","an","ian","en","in","ang","...