标签：div 姓名 tor pac iter ons opera 有序 自定义数据类型
引入#include<algorithm>
算法简介：
1.find
#include<iostream> using namespace std; #include <vector> #include <algorithm> #include <string> //常用查找算法 //find //查找 内置数据类型 void test01() { vector<int>v; for (int i = 0; i < 10; i++) { v.push_back(i); } //查找 容器中 是否有 5 这个元素 vector<int>::iterator it = find(v.begin(), v.end(), 5); if (it == v.end()) { cout << "没有找到！" << endl; } else { cout << "找到： " << *it << endl; } } class Person { public: Person(string name, int age) { this->m_Name = name; this->m_Age = age; } //重载 == 底层find知道如何对比person数据类型 bool operator==( const Person & p) { if (this->m_Name == p.m_Name && this->m_Age == p.m_Age) { return true; } else { return false; } } string m_Name; int m_Age; }; //查找 自定义数据类型 void test02() { vector<Person>v; //创建数据 Person p1("aaa", 10); Person p2("bbb", 20); Person p3("ccc", 30); Person p4("ddd", 40); //放入到容器中 v.push_back(p1); v.push_back(p2); v.push_back(p3); v.push_back(p4); Person pp("bbb", 20); vector<Person>::iterator it = find(v.begin(), v.end(), pp); if (it == v.end()) { cout << "没有找到" << endl; } else { cout << "找到元素 姓名：" << it->m_Name << " 年龄： " << it->m_Age << endl; } } int main() { //test01(); test02(); system("pause"); return 0; }
2.find_if
#include<iostream> using namespace std; #include <vector> #include <algorithm> #include <string> //常用查找算法 find_if //1、查找内置数据类型 class GreaterFive { public: bool operator()(int val) { return val > 5; } }; void test01() { vector<int>v; for (int i = 0; i < 10; i++) { v.push_back(i); } vector<int>::iterator it = find_if(v.begin(), v.end(), GreaterFive()); if (it == v.end()) { cout << "没有找到" << endl; } else { cout << "找到大于5的数字为： " << *it << endl; } } //2、查找自定义数据类型 class Person { public: Person(string name, int age) { this->m_Name = name; this->m_Age = age; } string m_Name; int m_Age; }; class Greater20 { public: bool operator()(Person &p) { return p.m_Age > 20; } }; void test02() { vector<Person>v; //创建数据 Person p1("aaa", 10); Person p2("bbb", 20); Person p3("ccc", 30); Person p4("ddd", 40); v.push_back(p1); v.push_back(p2); v.push_back(p3); v.push_back(p4); //找年龄大于20的人 vector<Person>::iterator it = find_if(v.begin(), v.end(), Greater20()); if (it == v.end()) { cout << "没有找到" << endl; } else { cout << "找到姓名： " << it->m_Name << " 年龄： " << it->m_Age << endl; } } int main() { //test01(); test02(); system("pause"); return 0; }
3.adjacent_find
#include<iostream> using namespace std; #include <vector> #include <algorithm> //常用查找算法 adjacent_find void test01() { vector<int>v; v.push_back(0); v.push_back(2); v.push_back(0); v.push_back(3); v.push_back(1); v.push_back(4); v.push_back(3); v.push_back(3); vector<int>::iterator pos = adjacent_find(v.begin(), v.end()); if (pos == v.end()) { cout << "未找到相邻重复元素" << endl; } else { cout << "找到相邻重复元素：" << *pos << endl; } } int main() { test01(); system("pause"); return 0; }
4.binary_search
#include<iostream> using namespace std; #include <vector> #include <algorithm> //常用查找算法 binary_search void test01() { vector<int>v; for (int i = 0; i < 10; i++) { v.push_back(i); } //v.push_back(2); 如果是无序序列，结果未知！ //查找容器中是否有9 元素 //注意：容器必须是有序的序列 bool ret = binary_search(v.begin(), v.end(), 9); if (ret) { cout << "找到了元素" << endl; } else { cout << "未找到" << endl; } } int main() { test01(); system("pause"); return 0; }
5.count
#include<iostream> using namespace std; #include <vector> #include <algorithm> #include <string> //常用查找算法_count //1、统计内置数据类型 void test01() { vector<int>v; v.push_back(10); v.push_back(40); v.push_back(30); v.push_back(40); v.push_back(20); v.push_back(40); int num = count(v.begin(), v.end(), 40); cout << "40的元素个数为： " << num << endl; } //2、统计自定义数据类型 class Person { public: Person(string name, int age) { this->m_Name = name; this->m_Age = age; } bool operator==(const Person & p) { if (this->m_Age == p.m_Age) { return true; } else { return false; } } string m_Name; int m_Age; }; void test02() { vector<Person>v; Person p1("刘备", 35); Person p2("关羽", 35); Person p3("张飞", 35); Person p4("赵云", 30); Person p5("曹操", 40); //将人员插入到容器中 v.push_back(p1); v.push_back(p2); v.push_back(p3); v.push_back(p4); v.push_back(p5); Person p("诸葛亮", 35); int num = count(v.begin(), v.end(), p); cout << "和诸葛亮同岁数的人员个数为：" << num << endl; } int main() { //test01(); test02(); system("pause"); return 0; }
6.count_if
#include<iostream> using namespace std; #include <vector> #include <algorithm> //常用查找算法 count_if //统计内置数据类型 class Greater20 { public: bool operator()(int val) { return val > 20; } }; void test01() { vector<int>v; v.push_back(10); v.push_back(40); v.push_back(30); v.push_back(20); v.push_back(40); v.push_back(20); int num = count_if(v.begin(), v.end(), Greater20()); cout << "大于20的元素个数为： " << num << endl; } class Person { public: Person(string name, int age) { this->m_Name = name; this->m_Age = age; } string m_Name; int m_Age; }; class AgeGreater20 { public: bool operator()(const Person& p) { return p.m_Age > 20; } }; //统计自定义数据类型 void test02() { vector<Person>v; Person p1("刘备", 35); Person p2("关羽", 35); Person p3("张飞", 35); Person p4("赵云", 40); Person p5("曹操", 20); v.push_back(p1); v.push_back(p2); v.push_back(p3); v.push_back(p4); v.push_back(p5); //统计 大于20岁人员个数 int num = count_if(v.begin(), v.end(), AgeGreater20()); cout << "大于20岁的人员个数为：" << num << endl; } int main() { //test01(); test02(); system("pause"); return 0; }
标签：div 姓名 tor pac iter ons opera 有序 自定义数据类型
原文地址：https://www.cnblogs.com/xiximayou/p/12114737.html
