STLでベクトルを実装するC++プログラム

ベクトルには、要素が挿入または削除されたときに動的配列のように自動的にサイズを変更する機能があり、コンテナはストレージを自動的に処理します。ベクトル要素は、イテレータを使用してアクセスおよびトラバースできるように、連続したストレージに配置されます。データは、ベクトルの最初、中間、または最後で挿入または消去できます。

機能と説明：

List of functions used here:
   v.size() = Returns the size of vector.
   v.push_back() = It is used to insert elements to the vector from end.
   v.pop_back() = To pop out the value from the vector from back.
   v.capacity() = Returns the size of the storage space currently allocated to the vector as number of elements.
   v.clear() = Clears the vector.

サンプルコード

#include <iostream>
#include <vector>
using namespace std;
int main() {
   vector<int> v;
   vector<int>::iterator it;
   int c, i;
   while (1) {
      cout<<"1.Size of the Vector"<<endl;
      cout<<"2.Insert Element into the Vector"<<endl;
      cout<<"3.Delete Last Element of the Vector"<<endl;
      cout<<"4.Display the capacity of vector"<<endl;
      cout<<"5.Display by Iterator"<<endl;
      cout<<"6.Clear the Vector"<<endl;
      cout<<"7.Exit"<<endl;
      cout<<"Enter your Choice: ";
      cin>>c;
      switch(c) {
         case 1:
            cout<<"Size of Vector: ";
            cout<<v.size()<<endl;
         break;
         case 2:
            cout<<"Enter value to be inserted: ";
            cin>>i;
            v.push_back(i);
         break;
         case 3:
            cout<<"Delete Last Element Inserted:"<<endl;
            v.pop_back();
         break;
         case 4:
            cout<<"Displaying capacity of vector: ";
            cout<<v.capacity()<<endl;
         break;
         case 5:
            cout<<"Displaying Vector by Iterator: ";
            for (it = v.begin(); it != v.end(); it++) {
               cout<<*it<<" ";
            }
            cout<<endl;
         break;
         case 6:
            v.clear();
            cout<<"Vector Cleared"<<endl;
         break;
         case 7:
            exit(1);
         break;
         default:
            cout<<"Wrong Choice"<<endl;
      }
   }
   return 0;
}

出力

1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 1
Size of Vector: 0
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 2
Enter value to be inserted: 7
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 2
Enter value to be inserted: 6
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 2
Enter value to be inserted: 4
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 2
Enter value to be inserted: 3
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 2
Enter value to be inserted: 5
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 4
Displaying capacity of vector: 8
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 5
Displaying Vector by Iterator: 7 6 4 3 5
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 3
Delete Last Element Inserted:
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 5
Displaying Vector by Iterator: 7 6 4 3
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 6
Vector Cleared
1.Size of the Vector
2.Insert Element into the Vector
3.Delete Last Element of the Vector
4.Display the capacity of vector
5.Display by Iterator
6.Clear the Vector
7.Exit
Enter your Choice: 7
Exit.