multiset-lower_bound

////////////////////////////////////////
//      2018/05/04 17:36:15
//      multiset-lower_bound

// return an iteror to the first element greater than a certain value
#include <iostream>
#include <map>
#include <string>
#include <fstream>

using namespace std;

int main(){
    typedef multimap<char, string> M1;
    typedef M1::value_type v_t1;
    M1 m1;

    typedef multimap<string, char, less<string>> M2;
    typedef M2::value_type v_t2;
    M2 m2;

    string word;
    int counter = 0;

    ifstream In(".\word.txt");
    if (In.good()){
        while (1){
            getline(In, word);
            char ch = word.at(0);
            // file is sorted
            if (ch != 'A' && ch != 'a'){
                break;
            }else{
                // for counting of words
                m1.insert(v_t1(ch, word));
                // for upper_lower bound
                m2.insert(v_t2(word,ch));
            }
            counter++;
        }
        In.close();
    }

    cout << "System Dictionary consists " << counter << " word with first letter 'a' or 'A'" << endl;
    cout << m1.count('A') << " words start with 'A'" << endl;
    cout << m1.count('a') << " words start with 'a'" << endl;

    M2::iterator low = m2.lower_bound("Aba");
    M2::iterator upp = m2.upper_bound("Ade");

    cout << "Range of the words form 'Aba' to 'Ade':" << endl;
    while (low != upp){
        cout << low->first << endl;
        low++;
    }
    return 0;
}

/*
OUTPUT:
    System Dictionary consists 61 word with first letter 'a' or 'A'
    14 words start with 'A'
    47 words start with 'a'
    Range of the words form 'Aba' to 'Ade':
    Abolish
    Action
    Acute
*/