If you want speed then fastest language is C++.
You can use std::sort for sorting purposes with parallel execution policy std::execution::par_unseq (which enables multi-threaded multi-core parallel sort).
As you can notice in my code below, I did arg-sort, because you wished for it. But in C++ it is not really necessary, it is enough to do regular sort, for two reasons.
One is because of cache locality, swapping data elements themselves instead of indices is faster because sorting algorithms are often more or less cache friendly, meaning that swapping/comparing nearby-in-memory elements happens often.
Second is because swapping of elements in std::sort is done through std::swap, which in turn uses std::move, this move function swaps classes like std::string very efficiently by just swapping pointers to data instead of copying data itself.
From above it follows that doing arg-sort instead of regular sort might be even slower.
Following code snippet first creates small example file with several data tuples that you provided. In real case you should remove this file writing code so that you don't overwrite your file. At the end it outputs to new file.
After program finishes see created files data.in and data.out.
Try it online!
#include <iostream>
#include <vector>
#include <string>
#include <fstream>
#include <tuple>
#include <execution>
#include <algorithm>
int main() {
{
std::ofstream f("data.in");
f << R"(
7, 38, banana
9, 27, pear
4, 99, orange
1, 15, apple
)";
}
std::vector<std::tuple<int, int, std::string>> data;
{
std::ifstream f("data.in");
std::string c;
while (true) {
int a = 0, b = 0;
char comma = 0;
c.clear();
f >> a >> comma >> b >> comma >> c;
if (c.empty() && !f)
break;
data.push_back({a, b, c});
}
}
std::vector<size_t> idx(data.size());
for (size_t i = 0; i < idx.size(); ++i)
idx[i] = i;
std::sort(std::execution::par_unseq, idx.begin(), idx.end(),
[&data](auto const & i, auto const & j){
auto const & [_0, x0, y0] = data[i];
auto const & [_1, x1, y1] = data[j];
if (x0 < x1)
return true;
else if (x0 == x1)
return y0 > y1;
else
return false;
});
{
std::ofstream f("data.out");
for (size_t i = 0; i < idx.size(); ++i) {
auto const & [x, y, z] = data[idx[i]];
f << x << ", " << y << ", " << z << std::endl;
}
}
}
Input:
7, 38, banana
9, 27, pear
4, 99, orange
1, 15, apple
Output:
1, 15, apple
9, 27, pear
7, 38, banana
4, 99, orange
