std::vector::resize() बनाम std::vector::reserve() सी++ में

जब कोई तत्व डाला या हटाया जाता है, तो वेक्टर स्वचालित रूप से गतिशील सरणी की तरह आकार बदलने की क्षमता रखता है, कंटेनर स्वचालित रूप से अपने भंडारण को संभालता है।

वेक्टर आकार () और वेक्टर रिजर्व () के बीच मुख्य अंतर यह है कि आकार बदलने () का उपयोग वेक्टर के आकार को बदलने के लिए किया जाता है जहां रिजर्व () नहीं होता है। आरक्षित () का उपयोग केवल स्मृति को पुन:आवंटित किए बिना निर्दिष्ट तत्वों की कम से कम संख्या को संग्रहीत करने के लिए किया जाता है। लेकिन आकार बदलने में () यदि संख्या वर्तमान संख्या से छोटी है तो यह मेमोरी का आकार बदल देती है और इसके ऊपर की अतिरिक्त जगह को हटा देती है।

वेक्टर ::आकार बदलें ()

Vector resize() is used to change its size.

उदाहरण

स्रोत कोड के चरण:

Begin
   Declare a variable v of vector type.
   Declare another variable it as iterator of vector type.
   Declare another two variable c and i to the ineger datatype.
   while (TRUE) do
      print “1.Size of the Vector”.
      print “2.Insert Element into the Vector”.
      print “3.Resize the vector”.
      print “4.Display by Iterator”.
      print “5.Exit”.
      print “Enter your Choice:”.
      Enter the value of variable c.
      Switch(c)
         Case 1.
            Print “Size of Vector:”.
            Call size() function to print the size of the vector.
            Break.
         Case 2.
            Print “Enter value to be inserted:”.
            Enter the value of variable i.
            Call push_back() function to input the values in the vector.
            Break.
         Case 3.
            Print “Resize the vector elements:”.
            Call resize() function to resize the vector.
            Break.
         Case 4.
           Print “Displaying Vector by Iterator:”.
            for (it = v.begin(); it != v.end(); it++)
               print the value of iterator it.
            Break.
         case 5.
            call exit() function to take exit.
            break.
         Default.
            Print “Wrong choice”.
End.

उदाहरण

#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.Resize the vector"<<endl;
      cout<<"4.Display by Iterator"<<endl;
      cout<<"5.Exit"<<endl;
      cout<<"Enter your Choice: ";
      cin>>c;
      switch(c) {
         case 1:
            cout<<"Size of Vector: ";
            cout<<v.size()<<endl; //printing the size of the vector
            break;
         case 2:
            cout<<"Enter value to be inserted: ";
            cin>>i;
            v.push_back(i); //inserting values
            break;
         case 3:
            cout<<"Resize the vector elements:"<<endl;
            v.resize(4); //resize the vector
            break;
         case 4:
            cout<<"Displaying Vector by Iterator: ";
            for (it = v.begin(); it != v.end(); it++) //printing all values of the vector {
               cout<<*it<<" ";
            }
            cout<<endl;
            break;
         case 5:
            exit(1);
            break;
         default:
            cout<<"Wrong Choice"<<endl;
      }
   }
   return 0;
}

आउटपुट

1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 1
Size of Vector: 0
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 1
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 2
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 4
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 5
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 5
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 4
Displaying Vector by Iterator: 1 2 4 5 5
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 3
Resize the vector elements:
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 4
Displaying Vector by Iterator: 1 2 4 5
1.Size of the Vector
2.Insert Element into the Vector
3.Resize the vector
4.Display by Iterator
5.Exit
Enter your Choice: 5

वेक्टर::रिजर्व ()

वेक्टर रिजर्व () इंगित करता है कि वेक्टर इस तरह बनाया गया है कि यह कम से कम निर्दिष्ट तत्वों की संख्या को स्मृति को पुनः आवंटित किए बिना संग्रहीत कर सकता है। उदाहरण में चरण

एल्गोरिदम

Begin
   Declare a variable v of vector type.
   Declare another variable it as iterator of vector type.
   Declare another two variable c and i to the ineger datatype.
   while (1) do
      print “1.Size of the Vector”.
      print “2.Insert Element into the Vector”.
      print “3.Reserve the vector”.
      print “4.Display by Iterator”.
      print “5.Exit”.
      print “Enter your Choice:”.
      Enter the value of variable c.
      Switch(c)
         Case 1.
            Print “Size of Vector:”.
            Call size() function to print the size of the vector.
            Break.
         Case 2.
            Print “Enter value to be inserted:”.
            Enter the value of variable i.
            Call push_back() function to input the values in the vector.
            Break.
         Case 3.
            Print “Reserve the vector elements:”.
            Call reserve() function to reserve the size of the vector.
               Break.
         Case 4.
            Print “Displaying Vector by Iterator:”.
            for (it = v.begin(); it != v.end(); it++)
               print the value of iterator it.
            Break.
         case 5.
            call exit() function to take exit.
            break.
      Default.
         Print “Wrong choice”.
End.

उदाहरण

#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.Reserve the vector"<<endl;
      cout<<"4.Display by Iterator"<<endl;
      cout<<"5.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<<"Reserve the vector elements."<<endl;
            v.reserve(100); //reserve the vector elements
            break;
         case 4:
            cout<<"Displaying Vector by Iterator: ";
            for (it = v.begin(); it != v.end(); it++) {
               cout<<*it<<" ";
            }
            cout<<endl;
            break;
         case 5:
            exit(1);
            break;
         default:
            cout<<"Wrong Choice"<<endl;
      }
   }
   return 0;
}

आउटपुट

1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 1
Size of Vector: 0
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 1
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 2
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 3
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 4
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 2
Enter value to be inserted: 5
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 3
Reserve the vector elements.
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 4
Displaying Vector by Iterator: 1 2 3 4 5
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit
Enter your Choice: 4
Displaying Vector by Iterator: 1 2 3 4 5
1.Size of the Vector
2.Insert Element into the Vector
3.Reserve the vector
4.Display by Iterator
5.Exit