C++中常见的容器类使用方法举例（vector、deque、map、set）

cpp中常见的容器类有vector、list、deque、map、set、unordered_map和unordered_set。

下面将举例直接说明各个容器的使用方法。

综合示例

1. vector：动态数组，支持随机访问

#include <iostream>
#include <vector>using namespace std;int main()
{vector<int> v;// 添加元素v.push_back(1);v.push_back(2);v.push_back(3);// 遍历元素for (auto it = v.begin(); it != v.end(); ++it){cout << *it << " ";}cout << endl;// 访问元素cout << v[0] << endl;cout << v.at(1) << endl;// 删除元素v.erase(v.begin() + 1);// 大小和容量cout << v.size() << endl;cout << v.capacity() << endl;return 0;
}

2. list：双向链表，支持双向遍历和插入删除

#include <iostream>
#include <list>using namespace std;int main()
{list<int> l;// 添加元素l.push_back(1);l.push_back(2);l.push_back(3);l.push_front(0);// 遍历元素for (auto it = l.begin(); it != l.end(); ++it){cout << *it << " ";}cout << endl;// 访问元素cout << l.front() << endl;cout << l.back() << endl;// 删除元素l.pop_front();// 大小cout << l.size() << endl;return 0;
}

3. deque：双端队列，支持首尾插入删除和随机访问

#include <iostream>
#include <deque>using namespace std;int main()
{deque<int> d;// 添加元素d.push_back(1);d.push_front(0);d.push_back(2);// 遍历元素for (auto it = d.begin(); it != d.end(); ++it){cout << *it << " ";}cout << endl;// 访问元素cout << d[0] << endl;cout << d.at(1) << endl;// 删除元素d.pop_front();// 大小cout << d.size() << endl;return 0;
}

4. map：红黑树实现的关联数组，支持按键访问和遍历

#include <iostream>
#include <map>using namespace std;int main()
{map<string, int> m;// 添加元素m["apple"] = 1;m["banana"] = 2;m.insert(make_pair("orange", 3));// 遍历元素for (auto it = m.begin(); it != m.end(); ++it){cout << it->first << " " << it->second << endl;}// 访问元素cout << m["apple"] << endl;// 删除元素m.erase("banana");// 大小cout << m.size() << endl;return 0;
}

5. set：红黑树实现的集合，支持按值访问和遍历

#include <iostream>
#include <set>using namespace std;int main()
{set<int> s;// 添加元素s.insert(1);s.insert(2);s.insert(3);// 遍历元素for (auto it = s.begin(); it != s.end(); ++it){cout << *it << " ";}cout << endl;// 访问元素auto it = s.find(2);if (it != s.end()){cout << *it << endl;}// 删除元素s.erase(3);// 大小cout << s.size() << endl;return 0;
}

6. unordered_map：哈希表实现的关联数组，支持按键访问和遍历

#include <iostream>
#include <unordered_map>using namespace std;int main()
{unordered_map<string, int> um;// 添加元素um["apple"] = 1;um["banana"] = 2;um.insert(make_pair("orange", 3));// 遍历元素for (auto it = um.begin(); it != um.end(); ++it){cout << it->first << " " << it->second << endl;}// 访问元素auto it = um.find("apple");if (it != um.end()){cout << it->second << endl;}// 删除元素um.erase("banana");// 大小cout << um.size() << endl;return 0;
}

7. unordered_set：哈希表实现的集合，支持按值访问和遍历

#include <iostream>
#include <unordered_set>using namespace std;int main()
{unordered_set<int> us;// 添加元素us.insert(1);us.insert(2);us.insert(3);// 遍历元素for (auto it = us.begin(); it != us.end(); ++it){cout << *it << " ";}cout << endl;// 访问元素auto it = us.find(2);if (it != us.end()){cout << *it << endl;}// 删除元素us.erase(3);// 大小cout << us.size() << endl;return 0;
}

检索方法示例

• 根据下标检索的容器类有vector、deque
• 根据值检索的容器类有set、map、unordered_set、unordered_map

（感觉主要靠容器.find()方法、容器.count()方法或者还可以用algorithm库里面的find）

1. vector：根据下标检索

#include <iostream>
#include <vector>using namespace std;int main()
{vector<int> v = {1, 2, 3};// 访问元素cout << v[0] << endl;cout << v.at(1) << endl;// 判断元素是否在容器内if (v.size() > 0 && v[0] == 1){cout << "1 is in the vector." << endl;}return 0;
}

2. deque：根据下标检索

#include <iostream>
#include <deque>using namespace std;int main()
{deque<int> d = {1, 2, 3};// 访问元素cout << d[0] << endl;cout << d.at(1) << endl;// 判断元素是否在容器内if (d.size() > 0 && d[0] == 1){cout << "1 is in the deque." << endl;}return 0;
}

3. set：根据值检索

#include <iostream>
#include <set>using namespace std;int main()
{set<int> s = {1, 2, 3};// 查找元素auto it = s.find(2);if (it != s.end()){cout << *it << " is in the set." << endl;}// 判断元素是否在容器内if (s.count(1) > 0){cout << "1 is in the set." << endl;}return 0;
}

4. map：根据值检索

#include <iostream>
#include <map>using namespace std;int main()
{map<string, int> m = {{"apple", 1}, {"banana", 2}, {"orange", 3}};// 查找元素auto it = m.find("banana");if (it != m.end()){cout << it->second << " is in the map." << endl;}// 判断元素是否在容器内if (m.count("apple") > 0){cout << "apple is in the map." << endl;}return 0;
}

5. unordered_set：根据值检索

#include <iostream>
#include <unordered_set>using namespace std;int main()
{unordered_set<int> us = {1, 2, 3};// 查找元素auto it = us.find(2);if (it != us.end()){cout << *it << " is in the unordered_set." << endl;}// 判断元素是否在容器内if (us.count(1) > 0){cout << "1 is in the unordered_set." << endl;}return 0;
}

6. unordered_map：根据值检索

#include <iostream>
#include <unordered_map>using namespace std;int main()
{unordered_map<string, int> um = {{"apple", 1}, {"banana", 2}, {"orange", 3}};// 查找元素auto it = um.find("banana");if (it != um.end()){cout << it->second << " is in the unordered_map." << endl;}// 判断元素是否在容器内if (um.count("apple") > 0){cout << "apple is in the unordered_map." << endl;}return 0;
}