int main()
{
/* type of the container:
* - map: elements key/value pairs
* - string: keys have type string
* - float: values have type float
*/
typedef map<string,float> StringFloatMap;
StringFloatMap coll;
// insert some elements into the collection
coll["VAT"] = 0.15;
coll["Pi"] = 3.1415;
coll["an arbitrary number"] = 4983.223;
coll["Null"] = 0;
/* print all elements
* - iterate over all elements
* - element member first is the key
* - element member second is the value
*/
StringFloatMap::iterator pos;
for (pos = coll.begin(); pos != coll.end(); ++pos) {
cout << "key: \"" << pos->first << "\" "
<< "value: " << pos->second << endl;
}
}
int main()
{
/*create map/associative array
*-keys are strings
*-values are floats
*/
typedef map<string,float> StringFloatMap;
StringFloatMap stocks; // create empty container
//insert some elements
stocks["BASF"] = 369.50;
stocks["VW"] = 413.50;
stocks["Daimler"] = 819.00;
stocks["BMW"] = 834.00;
stocks["Siemens"] = 842.20;
//print all elements
StringFloatMap::iterator pos;
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << pos->first << "\t"
<< "price: " << pos->second << endl;
}
cout << endl;
//boom (all prices doubled)
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
pos->second *= 2;
}
//print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << pos->first << "\t"
<< "price: " << pos->second << endl;
}
cout << endl;
/*rename key from "VW" to "Volkswagen"
*-only provided by exchanging element
*/
stocks["Volkswagen"] = stocks["VW"];
stocks.erase("VW");
//print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << pos->first << "\t"
<< "price: " << pos->second << endl;
}
}
int main()
{
// create map / associative array
// - key are strings
// - values are floats
typedef map<string,float> StringFloatMap;
StringFloatMap stocks; // create empty container
// insert some elements
stocks["BASF"] = 369.50;
stocks["VW"] = 413.50;
stocks["Daimler"] = 819.00;
stocks["BMW"] = 834.00;
stocks["Siemens"] = 842.20;
// print all elements
StringFloatMap::iterator pos;
cout << left; // left-adjust values
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << setw(12) << pos->first
<< "Price: " << pos->second << endl;
}
cout << endl;
// boom (all prices doubled)
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
pos->second *= 2;
}
// print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << setw(12) << pos->first
<< "Price: " << pos->second << endl;
}
cout << endl;
// rename key from "VW" to "Volkswagen"
// - provided only by exchangeing element
stocks["Volkswagen"] = stocks["VW"];
stocks.erase("VW");
// print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << setw(12) << pos->first
<< "Price: " << pos->second << endl;
}
}
int main()
{
typedef map<string, float> StringFloatMap;
StringFloatMap coll;
coll["VAT"] = 0.15;
coll["Pi"] = 3.1415;
coll["an arbitrary number"] = 4983.223;
coll["Null"] = 0;
StringFloatMap::const_iterator cit;
for(cit = coll.begin(); cit != coll.end(); ++ cit)
{
cout<<"Key: \""<<cit->first<<"\" "
<<"Value: "<<cit->second<<endl;
}
cout<<endl;
return 0;
}
int main () {
/** Using Algorithms and Lambdas with Maps/Multimaps */
cout << "Example 1:" << endl;
map<string,double> i1_coll
{
{"tim", 9.9},
{"struppi", 11.7}
};
// square the value of each element:
for_each(i1_coll.begin(), i1_coll.end(),
[] (pair<const string, double>& elem){
elem.second *= elem.second;
});
// print each element
for_each(i1_coll.begin(), i1_coll.end(),
[] (const map<string,double>::value_type& elem) {
cout << elem.first << ": " << elem.second << endl;
});
/** Using a Map as an Associative Array */
cout << "Example 2:" << endl;
// Create map / associative array
// - keys are strings
// - values are floats
typedef map<string,float> StringFloatMap;
// create empty container
StringFloatMap stocks;
// insert some elements
stocks["BASF"] = 369.50;
stocks["VW"] = 413.50;
stocks["Diamler"] = 819.00;
stocks["BMW"] = 834.00;
stocks["Simens"] = 842.20;
// print all elements
StringFloatMap::iterator pos;
// left-adjust values
cout << left;
for (pos = stocks.begin(); pos != stocks.end(); ++pos){
cout << "stock: " << setw(12) << pos->first
<< "price: " << pos->second << endl;
}
cout << endl;
// boom (all prices doubled)
for (pos=stocks.begin(); pos != stocks.end(); ++ pos){
pos->second *= 2;
}
// print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << setw(12) << pos->first
<< "price: " << pos->second << endl;
}
cout << endl;
// rename key from "VW" to "Volkswagen"
// - provided only by exchanging element
stocks["Volkswagen"] = stocks["VW"];
stocks.erase("VW");
// print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << setw(12) << pos->first
<< "price: " << pos->second << endl;
}
cout << endl;
/** Using multimap as dictionary */
cout << "Example 3:" << endl;
// create multimap as string/string bictionary
multimap<string, string> dict;
// insert some elements in random order
dict.insert( {
{"day", "Tag"},
{"stange", "fremd"},
{"car", "Auto "},
{"smart", "elegant"},
{"trait", "Merkmal"},
{"strange", "seltsam"},
{"smart", "raffiniert"},
{"smart", "klug"},
{"clever", "raffiniert"}
});
// print all elements
cout.setf(ios::left, ios::adjustfield);
cout << ' ' << setw(10) << "english "
<< "german " << endl;
cout << setfill('-') << setw(20) << ""
<< setfill(' ') << endl;
for (const auto& elem : dict)
cout << ' ' << setw(10) << elem.first
<< elem.second << endl;
// pritn all values for key "smart"
string word("smart");
cout << word << ": " << endl;
for (auto pos = dict.lower_bound(word); pos != dict.upper_bound(word); ++pos){
cout << " " << pos->second << endl;
}
// print allkeys with value "raffiniert"
word = ("raffiniert");
cout << word << ": " << endl;
for(const auto& elem : dict) {
if (elem.second == word){
cout << " " << elem.first << endl;
}
}
/** Finding elements with certain values */
cout << "Example 4:" << endl;
// map with floats as key and value
// - initializing keys and values are automatically converted to float
map<float,float> i4_coll
{
{1,7}, {2,4}, {3,2}, {4,3}, {5,6}, {6,1}, {7,3}
};
// search an element with KEY 3.0 (logarithmic omplexity)
auto posKey = i4_coll.find(3.0);
if (posKey != i4_coll.end()) {
cout << "key 3.0 found ("
<< posKey->first << ":"
<< posKey->second << ")" << endl;
}
// search an element with VALUE 3.0 (linear complexity)
auto posVal = find_if(i4_coll.begin(),i4_coll.end(),
[] (const pair<float,float>& elem) {
return elem.second == 3.0;
});
if (posVal != i4_coll.end()) {
cout << "Value 3.0 found ("
<< posVal->first << ":"
<< posVal->second << ")" << endl;
}
/** Maps, Strings and sorting Criterion at runtime */
cout << "Example 5:" << endl;
// create a container with the default comparsion criterion
StringStringMap i5_coll;
fillAndPrint(i5_coll);
// create object for case-insensitive comparsions
RuntimeStringCmp ignorecase(RuntimeStringCmp::nocase);
// create a container with the case-insensitive comparsions criterion
StringStringMap i5_coll_ins(ignorecase);
fillAndPrint(i5_coll_ins);
exit(EXIT_SUCCESS);
};
