C++ Tutorial/deque/transform
Checking if One Container Is Less Than or Greater Than Another
<source lang="cpp">#include <algorithm>
- include <deque>
- include <vector>
- include <iostream>
using namespace std; template <class T> void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){
std::cout << *i << endl;
}
} int main( ) {
const int data1[] = { 200, 250, 250, 100, 500, 500, 400 };
const int data2[] = { 200, 200, 300, 500, 400, 400 };
// create and initialize vectors to hold the debts
vector<int> debts1( data1,data1 + sizeof( data1 ) / sizeof( data1[0] ) );
vector<int> debts2( data2,data2 + sizeof( data2 ) / sizeof( data2[0] ) );
// sort into descending order
sort( debts1.begin(), debts1.end(), greater<int>() );
sort( debts2.begin(), debts2.end(), greater<int>() );
// display debts
print( debts1 );
print( debts2 );
if( debts1 > debts2 )
cout << "\nCollect from Group 1 first";
else
cout << "\nCollect from Group 2 first";
// store one group of debts in a different container
deque<int> debts2_deque( debts2.begin(), debts2.end() );
// compare the vector to the deque
if( lexicographical_compare( debts2_deque.begin(),
debts2_deque.end(), debts1.begin(), debts1.end() ) )
cout << "\nCollect from Group 1 in vector first";
else
cout << "\nCollect from Group 2 in deque first";
}</source>
Transform deque with boolean function
<source lang="cpp">#include <algorithm>
- include <deque>
- include <iostream>
using namespace std; bool logical_xor( bool a, bool b ); void print_result( const char* names[], const deque<bool>& print,const char* text ); int main( ) {
const char* contacts[] ={ "A", "J","S", "D", "R" };
const bool salesman1_data[] = { true, true, false, false, true };
const bool salesman2_data[] = { false, false, true, true, true };
const int num_customers = sizeof( salesman1_data ) / sizeof( salesman1_data[0] );
// create deques and initialize with above data
deque<bool> salesman1( salesman1_data,salesman1_data+num_customers );
deque<bool> salesman2( salesman2_data,salesman2_data+num_customers );
deque<bool> result( num_customers );
print_result( contacts, salesman1,"has been called by Salesman 1" );
print_result( contacts, salesman2,"has been called by Salesman 2" );
// customers called by both salesmen
transform( salesman1.begin(), salesman1.end(), salesman2.begin(),result.begin(), logical_and<bool>() );
print_result( contacts, result,"has been called by both salesmen" );
// customers called by at least one salesman
transform( salesman1.begin(), salesman1.end(), salesman2.begin(),result.begin(), logical_or<bool>() );
print_result( contacts, result,"has been called by at least one salesman" );
// customers called by only one salesman
transform( salesman1.begin(), salesman1.end(), salesman2.begin(),result.begin(), logical_xor );
print_result( contacts, result,"has been called by only one salesman" );
// customers not called by Salesman 1
transform( salesman1.begin(), salesman1.end(),result.begin(), logical_not<bool>() );
print_result( contacts, result,"has not been called by Salesman 1" );
} inline bool logical_xor( bool a, bool b ) {
return a ? !b : b;
} void print_result( const char* names[], const deque<bool>& which,const char* text ){
for( deque<bool>::size_type i = 0; i < which.size(); ++i )
if( which[i] )
cout << names[i] << " " << text << endl;
cout << endl;
}</source>
