C++常用数据结构操作示例

0. 前言

由于自己使用Python居多，对C++并不太熟悉，但是最近在刷算法题，所以这里简单整理总结一下C++常用数据结构的操作函数，以便方便查阅检索。

1. C++标准库常用数据结构

常用数据结构如下：

• string
• vector
• list
• queue和priority_queue
• set
• map
• stack

2. 常用数据结构操作示例

1. string

    //header file : 

     //declaration
    string s = "hello world!";

    // visit by subscript
    char c = s[2];//l
    const char cc = s.at(6);//w

    // get the length of the string
    int length = s.length();//12
    int size = s.size();//12

    // the string is empty or not
    bool is_empty = s.empty();//0

    // concat strings
    string t = "c++";
    s.append(t);//hello world!c++
    s += "Python!";//hello world!c++Python!

    // get substring
    string sub_str = s.substr(0, 5);//hello

    // find substring
    int pos = s.find("world");//6

    // insert operation
    s.insert(0, "Hi!");//Hi!hello world!c++Python!

    // compare operation
    string other = "NLP";
    bool cmp = other < s;//0

    // visit element by iterator
    for (auto i: s) {
        cout << i << endl;
    }

2. vector

    // header file :

    // declaration
    vector vec {2, 3, 4}; //[2, 3, 4]

    // size of vector
    int size = vec.size(); //3

    // the vector is empty or not
    bool is_empty = vec.empty(); // 0

    // visit by subscript
    auto e = vec.at(2);//4
    int m = vec[1];//3
    cout << e << m << endl;

    // append element at back
    vec.push_back(5); // [2, 3, 4, 5]

    // delete the last element
    vec.pop_back();//[2, 3, 4]

    // insert an element by iterator
    vec.insert(vec.begin(), 1); //[1, 2, 3, 4]

    // visit the first element and the last element
    cout << vec.front() << vec.back() << endl; // 14

    // visit by iterator
    auto iter = vec.begin();
    while (iter != vec.end()) {
        cout << *iter << endl;
        iter += 1;
    }

    // delete element by iterator
    auto item = vec.erase(vec.end() -2);

    cout << *item << endl;//4

    for (auto i: vec) {
        cout << i << endl;
    }

参考：

• c++string类的常用方法详解_c/c++_monkey_D_feilong的博客-CSDN博客
• C++ vector容器用法 -