relational data structures & strings (C++ STL)

#include "stdafx.h"
#include <cstdio>
 
#include "stdafx.h"
#include <cstdio>
#include <unordered_set>
#include <set>
#include <unordered_map>
#include <map>
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
 
using namespace std;
 
template<class T>
class test {
public:
    T a;
    T b;
};
 
string func(string sam) {
    sam += " world";
    return sam;
}
 
int main() {
 
    // pair은 대소비교 및 각 원소 접근이 가능하다. STL 원소로도 사용 가능.
    pair<int, int> p(100, 101);
    pair<int, int> p2(99, 101);
    pair<int, int> p3(100, 102);
    vector<pair<int, int>> v1;
    v1.push_back(p);
    v1.push_back(p2);
    v1.push_back(p3);
    sort(v1.begin(), v1.end()); // #include <algorithm>
    vector<pair<int, int>>::iterator it1;
    for (it1 = v1.begin(); it1 != v1.end(); it1++) {
        cout << it1->first << " " << (*it1).second << endl;
    }
 
    
    //map은 red black tree를 사용해서 insert delete search가 O(logN)이다. 자동정렬된다.
    map<string, int> data;
//INSERT
    data.insert(map<string, int>::value_type("void knife", 400));
    data.insert(map<string, int>::value_type("void knife", 10)); // 먼저온놈만 남는다!!
    data.insert(map<string, int>::value_type("killer sword", 330));
    data.insert(map<string, int>::value_type("gorgon hammer", 220));
    data.insert(map<string, int>::value_type("wand", 90));
    data.insert(data.begin(), map<string, int>::value_type("zsword", 550)); // 영향 없음..
    map<string, int>::iterator i1;
    for (i1 = data.begin(); i1 != data.end(); i1++) {
        cout << i1->first << " " << i1->second << endl;
    }
//FIND
    i1 = data.find("wand");
    if (i1 != data.end()) {
        cout << "found" << endl;
        //i1->first = s1; 키값은 바꿀 수 없다!! 다시 insert 해줘야됨. erase 하고
        i1->second = 1000;
    }
//ERASE
    data.erase("wand");
    i1 = data.begin();
    for (int i = 0; i < 3; i++) {
        i1++;
    }
    data.erase(i1);
    for (i1 = data.begin(); i1 != data.end(); i1++) {
        cout << i1->first << " " << i1->second << endl;
    }
 
//UPPER BOUNDS
    map<int,string> students;
    for (int i = 0; i < 10; i++) {
        string z1 = "sam hamington";
        z1.append(1, i + '0');
        students.insert(map<int,string>::value_type(i*10,z1));
    }
    map<int, string>::iterator im;
    im = students.upper_bound(23);
    for (map<int, string>::iterator im2 = im; im2 != students.end(); im2++) {
        cout << im2->first << " " << im2->second << endl;
    }
    
    //set은 red black tree를 사용해서 insert delete search가 O(logN)이다.
    
    set<string> jset;
//INSERT
    jset.insert("lexiographically");
    jset.insert("japan");
    jset.insert("jaPan");
    jset.insert("jApan");
    jset.insert("adam");
//ERASE
    jset.erase(jset.begin());
    jset.erase("jApan");
//FIND
    if (jset.find("japan") != jset.end()) {
        cout << "found" << endl;
    }
//ITERATE
    set<string>::iterator itr;
    for (itr = jset.begin(); itr != jset.end(); itr++) {
        cout << *itr << endl;
    }
//BOUNDS
    set<int> sset;
    for (int i = 1; i < 20; i++) sset.insert(i*10);
    set<int>::iterator sl, su;
    sl = sset.upper_bound(31);
    su = sset.upper_bound(122);
    for (set<int>::iterator sss = sl; sss != su; sss++) {
        cout << *sss << endl;
    }
 
    //unordered map이 우리가 기대하는 그 hash table이다..
    //insert delete index가 모두 상수이다. space complexity는 O(n)
    unordered_map<string, int> characters;
//INSERT
    characters.insert(unordered_map<string, int>::value_type("john doe", 10000));
    characters.insert(unordered_map<string, int>::value_type("jinhyuk jeon", 1990000));
    characters.insert(unordered_map<string, int>::value_type("sam white", 1000880));
    characters.insert(unordered_map<string, int>::value_type("baeyean whang", 10887000));
    characters.insert(unordered_map<string, int>::value_type("junho kim", 1000550));
    characters.insert(unordered_map<string, int>::value_type("junyong kim", 1003300));
    unordered_map<string, int>::iterator j1;
    for (j1 = characters.begin(); j1 != characters.end(); j1++) {
        cout << j1->first << " " << j1->second << endl;
    }
 
//FIND
    j1 = characters.find("sam white");
    if ( j1 != characters.end()) {
        cout << "founddd" << endl;
        j1->second = 111;
    }
 
//DELETE
    j1 = characters.begin();
    for (int i = 0; i < 3; i++) {
        j1++;
    }
    characters.erase(j1);
    characters.erase("john doe");
    for (j1 = characters.begin(); j1 != characters.end(); j1++) {
        cout << j1->first << " " << j1->second << endl;
    }
 
//SIZE, CLEAR
    cout << "size" << characters.size() << endl;
    characters.clear();
 
 
    //unordered set은 hash table을 사용해서 average index time이 constant이다.
    unordered_set<string> stringset;
// INSERT
    stringset.insert("hello world");
    stringset.insert("bye");
    stringset.insert("bye"); // 아무 일도 일어나지 않음
    // insert나 초기화의 순서가 iterator 순서를 보장하지 않는다!!
    unordered_set<int> jack;
    for (int i = 0; i < 100; i++) {
        jack.insert(i);
    }
    unordered_set<int>::iterator it2;
    for (it2 = jack.begin(); it2 != jack.end(); it2++) {
        cout << *it2 << " ";
    }
    cout << endl;
 
// FIND
    if (stringset.find("hello world") == stringset.end()) {
        cout << "not found" << endl;
    }
    else {
        cout << "found" << endl;
    }
    cout << stringset.size() << endl;
// ITERATE
    unordered_set<string>::iterator it;
    for (it = stringset.begin(); it != stringset.end(); it++) {
        cout << *it << endl;
    }
// ERASE
    std::unordered_set<std::string> myset =
    { "USA","Canada","France","UK","Japan","Germany","Italy", "jinhyuk" };
 
    myset.erase(myset.begin());                    // erasing by iterator
    myset.erase("France");                         // erasing by key
    myset.erase(myset.find("Japan"), myset.end()); // erasing by range
    for (it = myset.begin(); it != myset.end(); it++) {
        cout << *it << endl;
    }
// CLEAR
    myset.clear();
 
    //multiset
    cout << "start here" << endl << endl;
    multiset<int> mms;
    mms.insert(1);
    mms.insert(2);
    mms.insert(1);
    mms.insert(3);
    mms.insert(1);
    for (multiset<int>::iterator iii = mms.begin(); iii != mms.end(); iii++) {
        cout << *iii << endl;
    }
    if (mms.find(1) != mms.end()) {
        cout << "found" << endl;
    }
 
    // O(logN)
    cout << "counts " << mms.count(1) << endl;
 
    // strings
    string sam = "hi im string";
    char * sam3 = new char[50]; // char sam3[50] 도 똑같이 동작한다
    scanf("%[^\n]", sam3);
    //char 배열을 string에 대입 가능
    sam = sam3;
    //string sam4 = sam3;
    cout << "ss4 " << sam << endl;
    //scanf("%s", &sam); 스트링 입력 안된다
    cout << sam[3] << endl;
    cout << sam.size() << endl;
    int i = 0;
    while (sam[i] != '\0') {
        cout << sam[i] << endl;
        i++;
    }
    sam = func("hello");
    cout << sam.c_str() << endl;
    string sam2 = "what is this";
    cout << sam2 << endl; // need to include <string>
    vector<string> v2;
    v2.push_back("hello");
    v2.push_back("world");
    cout << v1.size() << " " << v2.at(0) << " " << v2.at(1) << endl;
    while (1) {}
    return 0;
}