How to sort a Vector in descending order using STL in C++?

November 10, 2020   C++ Programming , STL

In this article, we will be discussing how to sort a given vector in descending with the help of the STL algorithm.

ALSO READ : How to sort a vector in ascending order

Example:

Input:
vec = {12, 35, 44, 54, 23, 24, 87},
Output: {87, 54, 44, 35, 24, 23, 12}

Input:
vec = {12, 17, 25, 74, 60, 52,11},
Output: {74, 60, 52, 25, 17, 12, 11 }

How to sort a vector in descending order :

We are going to use a predefined function that has been described in STL algorithms this function is sort(). Using this function we will get our output.

Syntax

sort(vec.begin(), vec.end() , greater<T>());

//here T is the data type { ex: int, float, double ..

What is the use of greater<T>() :

This is a predefined function inside the STL library who resembles two elements while sorting and return greater element first. This is the logic for applying greater<T>() for sorting the vector in descending order.

Implementation :

#include<iostream>
#include<vector>
#include <algorithm>
int main()
{
    // INtialize and store the vector
    std::vector<int> vec = {12, 35, 44, 54, 23, 24, 87};
    // We need to sort the vector the vector in descending order
    std::sort(vec.begin(), vec.end(),greater<int>());
    // Printout the sorted vector
    std::cout << "Sorted Vector : ";
    for (int i = 0; i < vec.size(); i++)
    {
        std::cout << vec1.at(i) << " ";
    }
    std::cout << std::endl;
    return 0;
}

Output

Sorted Vector : 87 54 44 35 24 23 12