Trong hướng dẫn này, ta thảo luận về Multiset trong C++ STL.
Multiset là container liên hợp tương tự set, nhưng khác ở chỗ multiset có thể chứa các giá trị trùng lặp.
Ví dụ
#include <iostream> #include <set> #include <iterator> using namespace std; int main(){ multiset <int, greater <int> > gquiz1; gquiz1.insert(40); gquiz1.insert(30); gquiz1.insert(60); gquiz1.insert(20); gquiz1.insert(50); gquiz1.insert(50); gquiz1.insert(10); multiset <int, greater <int> > :: iterator itr; cout << "\nThe multiset gquiz1 is : "; for (itr = gquiz1.begin(); itr != gquiz1.end(); ++itr) cout << '\t' << *itr; cout << endl; multiset <int> gquiz2(gquiz1.begin(), gquiz1.end()); cout << "\nThe multiset gquiz2 after assign from gquiz1 is : "; for (itr = gquiz2.begin(); itr != gquiz2.end(); ++itr) cout << '\t' << *itr; cout << endl; cout << "\ngquiz2 after removal of elements less than 30 : "; gquiz2.erase(gquiz2.begin(), gquiz2.find(30)); for (itr = gquiz2.begin(); itr != gquiz2.end(); ++itr) cout << '\t' << *itr; int num = gquiz2.erase(50); cout << "\ngquiz2.erase(50) : " << num << " removed \t" ; for (itr = gquiz2.begin(); itr != gquiz2.end(); ++itr) cout << '\t' << *itr; cout << endl; cout << "gquiz1.lower_bound(40) : " << *gquiz1.lower_bound(40) << endl; cout << "gquiz1.upper_bound(40) : " << *gquiz1.upper_bound(40) << endl; cout << "gquiz2.lower_bound(40) : " << *gquiz2.lower_bound(40) << endl; cout << "gquiz2.upper_bound(40) : " << *gquiz2.upper_bound(40) << endl; return 0; }Đầu ra
The multiset gquiz1 is : 60 50 50 40 30 20 10 The multiset gquiz2 after assign from gquiz1 is : 10 20 30 40 50 50 60 gquiz2 after removal of elements less than 30 : 30 40 50 50 60 gquiz2.erase(50) : 2 removed 30 40 60 gquiz1.lower_bound(40) : 40 gquiz1.upper_bound(40) : 30 gquiz2.lower_bound(40) : 40 gquiz2.upper_bound(40) : 60