How to reverse a Vector using STL in C++?
Given a vector, reverse this vector using STL in C++.
Example:
Input: vec = {1, 45, 54, 71, 76, 12}
Output: {12, 76, 71, 54, 45, 1}
Input: vec = {1, 7, 5, 4, 6, 12}
Output: {12, 6, 4, 5, 7, 1}Approach: Reversing can be done with the help of reverse() function provided in STL. The Time complexity of the reverse() is O(n) where n is the length of the string.
Syntax:
reverse(start_index, last_index);
CPP
// C++ program to reverse Vector// using reverse() in STL#include <bits/stdc++.h>using namespace std;int main(){ // Get the vector vector<int> a = { 1, 45, 54, 71, 76, 12 }; // Print the vector cout << "Vector: "; for (int i = 0; i < a.size(); i++) cout << a[i] << " "; cout << endl; // Reverse the vector reverse(a.begin(), a.end()); // Print the reversed vector cout << "Reversed Vector: "; for (int i = 0; i < a.size(); i++) cout << a[i] << " "; cout << endl; return 0;} |
Output:
Vector: 1 45 54 71 76 12 Reversed Vector: 12 76 71 54 45 1
Time Complexity: O(n) where n is the length of the string.
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