目录​​​​​​​

1.常用遍历算法

for_each

transform

2.常用查找算法

find 

find_if 

adjacent_find

binary_search

count

count_if

---

1.常用遍历算法

for_each

#include<bits/stdc++.h>
using namespace std;void print(int v)
{cout << v << ' ';
}class print2
{
public:void operator()(int v){cout << v << ' ';}
};int main()
{vector<bool> v;v.push_back(1);v.push_back(1);v.push_back(0);v.push_back(0);v.push_back(1);for_each(v.begin(),v.end(),print);cout << endl;//仿函数for_each(v.begin(),v.end(),print2());return 0;
}

 

transform

必须提前开辟空间 

#include<bits/stdc++.h>
using namespace std;class trans
{
public:int operator()(int v){return v + 200;}
};class print
{
public:void operator()(int v){cout << v << ' ';}
};int main()
{vector<bool> v;v.push_back(1);v.push_back(1);v.push_back(0);v.push_back(0);v.push_back(1);vector<int> v1;v1.resize(v.size());transform(v.begin(),v.end(),v1.begin(),trans());for_each(v1.begin(),v1.end(),print());
}

 

2.常用查找算法

find 

#include<bits/stdc++.h>
using namespace std;int main()
{vector<int> v;v.push_back(4);v.push_back(5);v.push_back(2);v.push_back(8);v.push_back(1);vector<int>::iterator it;it = find(v.begin(),v.end(),8);if(it != v.end()) cout << "找到了" << endl;
}

 

自定义数据类型 

#include<bits/stdc++.h>
using namespace std;class person
{
public:person(string name,int a){this -> name = name;this -> a = a;}bool operator==(const person &p){if(this -> name == p.name && this -> a == p.a)return true;else return false;}string name;int a;
};int main()
{vector<person> v;person p1("aa",99);v.push_back(p1);vector<person>::iterator it = find(v.begin(),v.end(),p1);if(it != v.end()) cout << "找到了" << endl;
}

 

find_if 

#include<bits/stdc++.h>
using namespace std;class dayu5
{
public:bool operator()(int v){return v > 5;}
};int main()
{vector<int> v;v.push_back(3);v.push_back(2);v.push_back(9);v.push_back(4);v.push_back(10);vector<int>::iterator it = find_if(v.begin(),v.end(),dayu5());if(it != v.end()) cout << "找到了" << endl;
}

adjacent_find

 

#include<bits/stdc++.h>
using namespace std;int main()
{vector<int> v;v.push_back(3);v.push_back(2);v.push_back(3);v.push_back(4);v.push_back(4);vector<int>::iterator it = adjacent_find(v.begin(),v.end());cout << *it << endl;
}

 

binary_search

 

必须是有序的序列 

#include<bits/stdc++.h>
using namespace std;int main()
{vector<int> v;v.push_back(1);v.push_back(2);v.push_back(3);v.push_back(4);v.push_back(4);bool ret = binary_search(v.begin(),v.end(),3);cout << ret << endl;return 0;}

 

count

 

统计自定义数据类型数目时，要重载==符号 

#include<bits/stdc++.h>
using namespace std;int main()
{vector<int> v;v.push_back(1);v.push_back(2);v.push_back(3);v.push_back(4);v.push_back(4);int num = count(v.begin(),v.end(),4);cout << num << endl;return 0;
}

 

count_if

 

#include<bits/stdc++.h>
using namespace std;class dayu2
{
public:bool operator()(int v){return v > 2;}
};int main()
{vector<int> v;v.push_back(1);v.push_back(2);v.push_back(3);v.push_back(4);v.push_back(4);int num = count_if(v.begin(),v.end(),dayu2());cout << num << endl;return 0;
}