C++ 程序在 STL 中实现 Set
Set 是抽象数据类型,其中每个元素必须唯一,因为元素的值将其标识。一旦将元素的值添加到 set 中,就无法修改该值,但可以删除该元素并添加该元素的修改后值。
函数和说明
Functions used here: st.size() = Returns the size of set. st.insert() = It is used to insert elements to the set. st.erase() = To delete the element from the set. st.find() = Returns an iterator to the search element in the set if found, else returns the iterator to end. st.begin() = Returns an iterator to the first element in the set. st.end() = Returns an iterator to the last element in the set.
示例代码
#include <iostream> #include <set> #include <string> #include <cstdlib> using namespace std; int main() { set<int> st; set<int>::iterator it; int c, i; while (1) { cout<<"1.Size of the Set"<<endl; cout<<"2.Insert Element into the Set"<<endl; cout<<"3.Delete Element of the Set"<<endl; cout<<"4.Find Element in a Set"<<endl; cout<<"5.Display the set: "<<endl; cout<<"6.Exit"<<endl; cout<<"Enter your Choice: "; cin>>c; switch(c) { case 1: cout<<"Size of the Set: "; cout<<st.size()<<endl; break; case 2: cout<<"Enter value to be inserted: "; cin>>i; st.insert(i); break; case 3: cout<<"Enter the element to be deleted: "; cin>>i; st.erase(i); break; case 4: cout<<"Enter the element to be found: "; cin>>i; it = st.find(i); if (it != st.end()) cout<<"Element "<<*it<<" found in the set" <<endl; else cout<<"No Element Found"<<endl; break; case 5: cout<<"Displaying Set by Iterator: "; for (it = st.begin(); it != st.end(); it++) { cout << (*it)<<" "; } cout<<endl; break; case 6: exit(1); break; default: cout<<"Wrong Choice"<<endl; } } return 0; }
输出
1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 1 Size of the Set: 0 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 2 Enter value to be inserted: 1 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 2 Enter value to be inserted: 7 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 2 Enter value to be inserted: 6 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 2 Enter value to be inserted: 4 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 3 Enter the element to be deleted: 1 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 4 Enter the element to be found: 7 Element 7 found in the set 1.Size of the Set 2.Insert Element into the Set 3.Delete Element of the Set 4.Find Element in a Set 5.Display the set: 6.Exit Enter your Choice: 6 Exit code: 1
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