Stl_ algorithm _ Find Algorithm (Find, find_if)

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Find, Find_if

/********************** Linear lookup O (n) find (); find_if (); Note: 1. The assumption is that the interval lookup algorithm can be used 2. An associative container (SET,MAP) has an equivalent member function find (); Time Complexity O ( Log (n)) 3.string has equivalent member function find (); **********************/#include <iostream> #include <cstdio> #include <string> #include <vector> #include <set> #include <algorithm> #include <functional> Using namespace STD;/*************************************************************************************STD:: Find Algorithm----------------------------------------- ---------------------------------------------Template <class Inputiterator, class t> Inputiterator find ( Inputiterator First, Inputiterator last, const t& value); Eg:template<class Inputiterator, Class t> Inputiterat Or find (inputiterator first, Inputiterator last, const t& value) {for (; first!=last; first++) if (*first==va    Lue) break;  return first; }**************************************************************************************//***************************************************************** STD::FIND_IF algorithm------------- -------------------------------------------------------------------------Template <class Inputiterator, class Predicate> inputiterator find_if (inputiterator First, inputiterator last, predicate pred); Eg:template<class INP Utiterator, Class predicate> Inputiterator find_if (inputiterator First, inputiterator last, predicate pred) {f    or (; first!=last; first++) if (pred (*first)) break;  return first; }**************************************************************************************/bool IsEven (int i); int    Main () {int myints[] = {10,30,20,40,20,10,30,40};    int * p;    Pointer to array element:p = Find (myints,myints+8,30);    ++p;    cout << "The element following" << *p << Endl; VectoR<int> Myvector (myints,myints+8);    Vector<int>::iterator it;    iterator to vector element:it = find (Myvector.begin (), Myvector.end (), 30);    ++it;    cout << "The element following" << *it << Endl;    Outputs the number Vector<int>::iterator it2 in the second 30 interval of the first---;    It2=find (It,myvector.end (), 30);    while (it!=it2) cout<<*it++<< ""; cout<<endl;/**--------------------------------find_if ()---------------------------------**///Find the first even-numbered it = Find_if (Myvector.begin (), Myvector.end (), IsEven);//function or Function object cout << "The first odd value is" << *it &lt    ;< Endl;    It2 = find_if (Myvector.begin (), Myvector.end (), Not1 (bind2nd (Modulus<int> (), 2))); cout << "The first odd value is" << *it2 << endl;/**--------------------------------associated Container--------------    -------------------**/set<int> S (myvector.begin (), Myvector.begin () +4); cout<< "Complexity is O (log (n)), find *s.find (+): =" <&Lt *s.find << endl;/**---------------------------------string----------------------------------**/string    St ("Angelababy");    String::size_type pos = st.find ("Baby"); if (pos! = string::npos) cout<< "Find it!"    <<endl; else cout<< "not find it!"    <<endl;    pos = St.find ("Baby"); if (pos! = string::npos) cout<< "Find it!"    <<endl; else cout<< "not find it!"    <<endl; return 0;} BOOL IsEven (int i) {return ((i%2) ==0);} /******output:the element Following, the element following, the first odd value I    S. The first odd value is 10 complexity is O (log (n)), find *s.find (+): = it! Find Not find it!******/

Stl_ algorithm _ Find Algorithm (Find, find_if)