STL---Collation commonly used in C + + implementation algorithm

Algorithm sort Quick Line

#include <algorithm>   //Note contains algorithm header file #include<iostream>using namespace Std;int main () {    int Arr[] = {1,9,8,4,3,6,0,11};    int length = sizeof (arr)/4;    the sort range for quick sort//sort is [start, end], which is used by default from small to large.    sort (arr, arr + 3);   Sorts only the first 3 sort    (arr + 2, arr + length);//Sorts the elements after the 2nd element. Sort    (arr, arr + length);//Sorts the entire array sort    (arr, arr + length, greater<int> ());//Sort the entire array from large to small    return 0;}

　　

Binary_search Two-point search

int arr[] = {0,3,5,7,10,15,19,20,22,24,27};int length = sizeof (arr)/4;bool isfind = True;isfind = Binary_search (arr + 2, Arr + length, 19); Binary search in [Start, end] keycout<< isfind << Endl;

Stack

#include <stack>   //note contains the stack header file #include<iostream>using namespace Std;int main () {    stack<int > s; Declares the type in the stack, and the stack name    s.push (3);    S.push (4);    into the stack    int length = S.size ();//Gets the number of stack elements    int top = S.top ();    Get stack top element (not out of stack)    s.pop ();    Out of stack    bool isEmpty = S.empty ();    return 0;}

Queue

#include <iostream> #include <queue>   //note contains the queue header file using namespace Std;int main () {    queue< string> Q;    string S;    Q.push ("Hello");  Queue    Q.push ("World");    cout<< Q.front () << Endl;   Hello gets the first element value of the team, but not the team    cout<< q.back () << Endl;    World gets the tail element value, but not the team    Q.pop ();   Team first element out team    cout<< Q.front () << Endl;   World    cout<< "Size" << q.size () << Endl;    cout<< "IsEmpty" << q.empty () <<endl;    return 0;}

　　

Set/multiset

Multiset/set uses the data structure of the balanced binary tree, and the insertion and lookup time complexity are log n.

Multiset and set use the same, with only one difference:

1. Duplicate elements can appear in the multiset.

2, the set does not appear duplicate elements, even if the addition of duplicate elements, will automatically go to the weight.

#include <iostream> #include <set>//multiset and set include the set header file using namespace Std;int main () {int arr[10] = {5,    1,2,4,6,4,3,5,8,8};//has a repeating element int i; Multiset<int> MS;    Create a Space Multiset collection for (i = 0; i < i++) {Ms.insert (arr[i]);  } Multiset<int>::iterator p; Declares an iterator that resembles the pointer for (P = ms.begin (); P! = Ms.end (); p++) {//ms.begin () returns an iterator that points to the first element of Multiset//ms.en    D () returns an iterator that points to the next position of the last element of Multiset cout << *p << "";    1 2 3 4 4 5 5 6 8 8} cout << Endl;   int length = Ms.size ();  The number of elements in the collection bool IsEmpty = Ms.empty ();   Whether the collection is empty int cnt = Ms.count (8);  Count occurrences of a number cout<< length << "<< isEmpty <<" "<< cnt << Endl; 10 0 2//Find element, if found, returns an iterator pointing to the found element.    If not found, returns the total number of elements in the multiset size p = ms.find (8);   if (*p! = Ms.size ()) {cout<< "found" << *p << Endl;   8 Ms.erase (*P); Removes all 8 from the collection, not just one。    cout<< "After delete, the size is" << ms.size () << Endl;    } else {cout<< "not found" <<endl; } return 0;}

Map/multimap

Both map and Multimap use hash algorithms.

The difference is that the key in the map appears only once, and Multimap can appear many times.

#include <iostream> #include <map>   //multimap and map include the set header file using namespace Std;int main () {    map <string, string> m;    m["one"] = "Hello";    m["n" = "World";    M.insert (pair<string, string> ("Three", "C + +"));    BOOL IsEmpty = M.empty ();    int length = M.size ();    string s = m["one"];  If found, return the corresponding value    cout<< s <<endl;   Hello    s = m["Four"];    If not found, it returns a type 0 value    cout<< s <<endl;  Returns the empty string    map<string, String>::iterator p;    p = m.find ("one");    cout<< P->second << Endl; Output one corresponds to the value--Hello    m.erase (p);  Delete a key for    (P = m.begin (); P! = M.end (); p++) {        cout<< p->second << "";  C + + World    }    m.clear ();//clear map    return 0;}

　　

C + + implementation algorithm Common STL---collation