常用查找算法

find

• find(iterator beg, iterator end, value);

title:Important
最常用的查找算法

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
 
class Person
{
public:
    Person(string name, int age)
    {
        this->m_name = name;
        this->m_age = age;
    }
    
    bool operator==(const Person& p)
    {
        return (this->m_name == p.m_name && this->m_age == p.age);
    }
    
    string m_name;
    int m_age;
};
 
void print(vector<int>& v)
{
    for(vector<int>::iterator it = v.begin(); it != v.end(); it++)
    {
        cout << *it << " ";
    }
    cout << endl;
}
 
int main()
{
    vector<int>v1;
    
    for(int i = 0; i < 10; i++)
    {
        v1.push_back(i);
    }
    print(v1);
    
    vector<int>iterator it = find(v1.begin(), v1.end(), 5);
    vector<int>iterator it2 = find(v1.begin(), v1.end(), 50);
    
    if(it == v1.end())
    {
        cout << "没有找到" << endl;
    }
    else{
        cout << "找到:" << *it << endl;
    }
    
    if(it2 == v1.end())
    {
        cout << "没有找到" << endl;
    }
    else{
        cout << "找到:" << *it << endl;
    }
    
    vector<Person>v2;
    Person p1("aaa", 10);
    Person p2("bbb", 20);
    Person p3("ccc", 30);
    Person p4("ddd", 40);
    v1.push_back(p1);
    v1.push_back(p2);
    v1.push_back(p3);
    v1.push_back(p4);
    
    Person pp("bbb", 20);
    vector<int>iterator it3 = find(v1.begin(), v1.end(), pp);
    
    if(it3 == v2.end())
    {
        cout << "没有找到" << endl;
    }
    else{
        cout << "找到:" << it->m_name << it->m_age << endl;
    }
    
    return 0;
}
/*output:
0 1 2 3 4 5 6 7 8 9
找到:5
没有找到
找到:bbb20
 
*/

find_if

• find_if();

#include <iostream>
using namespace std;
 
int main()
{
    
    return 0;
}

adjacent_find

• adjacent_find();

binary_search

• binary_search();

count

• count();

count_if

• count_if();