C++STL容器的常见代码（部分）-优快云博客

本文链接：https://blog.youkuaiyun.com/song0789/article/details/144157626

比赛前用来回忆的代码不是很完整

map

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve6()
{
    //一个映射,
    //map 一个元素仅出现一次，有序，默认从小到大
    //multimap 一个元素可以出现多次，有序，默认从小到大
    //unordered_map 一个元素仅出现一次，无序
    map<string, int> mp1;
    if (mp1.find("1") != mp1.end())
    {
        cout << "YES" << endl;
    }
    else
    {
        cout << "NO" << endl;
    }
    mp1.erase("1");
    mp1.clear();
    mp1["a"] = 1;
    mp1["b"] = 2;
    for (map<string, int>::iterator it = mp1.begin();it != mp1.end();it++)
    {
        cout << it->first << " " << it->second << endl;
    }
    for (auto &tonum : mp1)
    {
        cout << tonum.first << " " <<tonum.second<< endl;
    }

    return 0;
}

pair

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve/*8*/()
{
    pair<int, int> par1 = make_pair(1, 2);
    pair<int, int> par2 = { 1,2 };
    if (par1 == par2)
    {
        cout << "YES" << endl;
        cout << par1.first << par1.second << endl;
    }
    return 0;
}

set

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve5()
{
    //一个集合,在找特别分散但是数量不多的数字特别好用
    //set 一个元素要么在集合中，要么不在，出现一次，有序，默认从小到大
    //multiset 一个元素要么在集合中，要么不在，可以出现多次，有序，默认从小到大
    //unordered_set 一个元素要么在集合中，要么不在，出现一次，无序
    set<int> st;
    set<int, greater<int> >st1;//从大到小
    //通用st.size();st.clear();st.empty();
    st.insert(1);
    st.insert(2);
    st.insert(1);
    for (auto& tonum : st)
    {
        cout << tonum << endl;
    }
    //for(set<int>::iterator it=st.begin();it!=st.end();++it)cout<<*it<<endl;
    st.erase(1);
    cout << st.count(1)<<endl;
    cout << st.count(2) << endl;
    auto so = st.find(2);//返回迭代器
    cout << *so;
    //unorder_set<int> st2 无序
    //multiset_set<int> st3 多个数 
    return 0;
}

vector

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve2()
{
    vector<int> ssr(10, 10086);//（长度，数值）
    ssr.push_back(1);//开销大
    ssr.pop_back();//删除尾部
    ssr.clear();
    ssr.empty();
    ssr.size();//返回size_t,在相乘可能溢出
    int num1=100;
    ssr.resize(num1);//大补0，小就删    
    //一些如条件限制n*m的题目，用普通数组不好判断大小，就要使用vector限制
    vector<vector<int> > ssr1(100, vector<int>());//行，列
    for (auto& tonum : ssr)//auto
    {
        cout << tonum << endl;
    }
    
    return 0;
}

string

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve7/**/()
{
    string s1(10, '0');//第一个个数，第二个赋值
    string s2(10, '1');
    s1[0] = '1';
    string s3 = "12345678";
    //out << s1 + s2 << endl;
    cout << s3.substr(3,2) << endl;//第一个定位从下标3开始，第二个是子串长度，用来截取子串
    if (s1.find("101")!=string::npos)
    {
        cout << "YES" << endl;
    }
    else
    {
        cout << "NO" << endl;
    }
    cout << (s1.find(100)) << endl;
    s1.find(100);

    int ssr = stoi(s1);
    string s = to_string(ssr);
    //注意，尾接字符串用+=
    //find效率不高
    return 0;
}

stack

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve3()
{
    stack<int> stk;
    //我用的比较少，不如直接用vector
    stk.push(111);
    stk.push(222);
    stk.push(333);
    cout << stk.size() << endl;        
    stk.empty();
    /*for (auto& tonum : stk)   //不可以直接访问
        cout << tonum <<endl;*/
    cout<<stk.top();
    stk.pop();
    cout<<stk.top();
    return 0;
}

queue

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
int solve4()
{
    //不可访问内部元素
    queue <int> quq;
    quq.size();
    quq.empty();
    quq.push(11);
    quq.push(22);
    quq.push(33);
    cout << quq.front() << " " << quq.back() << endl;
    return 0;
}

priority_queue

#include <bits/stdc++.h>
#include"head.h"
using namespace std;
struct game
{
    int year;
    int money;
};
struct compare_outbig {
    bool operator()(const game& game1, const game& game2)
    {
        return game1.money < game2.money;//钱少的在堆下，多的在顶部，输出最大的
    }
};
struct compare_outsmall {
    bool operator()(const game& game1, const game& game2)
    {
        return game1.money > game2.money;//钱多的在堆下，少的在顶部，输出最小的
    }
};
int solve1() {
    priority_queue<int> out_big;
    priority_queue<int, vector<int>, greater<int> >out_small;
    priority_queue<game, vector<game>, compare_outbig> struct_out_big;
    priority_queue<game, vector<game>, compare_outsmall>struct_out_small;
    int n=1;
    while(n)
    {
        cin >> n;
        out_big.push(n);
        out_small.push(n);
    }
    cout << "out_big" << endl;
    while (!out_big.empty())
    {
        cout << out_big.top() << endl;
        out_big.pop();
    }
    cout << "out_small" << endl;
    while (!out_small.empty())
    {
        cout << out_small.top() << endl;
        out_small.pop();
    }
    int m = 1;
    while (m)
    {
        cin >> n >> m;
        game sample1;
        sample1.year = n;
        sample1.money = m;
        struct_out_big.push(sample1);
        struct_out_small.push(sample1);
    }
    cout << "struct_out_big" << endl;
    while (!struct_out_big.empty())
    {
        game sample1 = struct_out_big.top();
        cout <<"game_money:"<< sample1.money <<"game_:" <<sample1.year << endl;
        struct_out_big.pop();
    }
    cout << "struct_out_small" << endl;
    while (!struct_out_small.empty())
    {
        game sample1 = struct_out_small.top();
        cout << "game_money:" << sample1.money << "game_:" << sample1.year << endl;
        struct_out_small.pop();
    }
    return 0;
}