I'm not sure why you'd do this task with files, as it is very expensive to load files into the program. However, your task can be accomplished (that is if I accurately understand what you're asking; your question was not written very clearly).
First, make sure to include your proper headers from the STL
#include <iostream> // Assuming you have console IO functionality #include <filesystem> // Accessing all files in a directory for searching #include <fstream> // Loading files into the program #include <string> // Assuming you have names for bidders #include <vector> // Load the files' contents into a vector
As you may be able to somewhat tell from the includes and their explanations, here's my plan for the program:
- Store all auction files in a directory that ONLY has auction files. This will save time because the program won't have to check a bunch of files that we aren't interested in.
- Using
std::filesystem::directory_iterator, search through all the files in the directory from above and save their contents to an std::vector - Use a max function to determine the largest bid and output their name
In practice, that means we may want a vector of structs that have (1) the name of the bidder and (2) their bid. Then we compare all their bids using a max function (like stated above). When we find the max, we will be able to very easily find the name bidder that goes with that bid and output to the screen.
The .txt files (for my solution) have strictly two lines per file. The first line is the bidder's name, and the second line is the bidder's bid. This will line up exactly with the struct we'll use for loading these files into the program.
So, here's the program (make sure you're using C++17):
#include <filesystem> // std::filesystem : path, directory_iterator, current_path, parent_path #include <fstream> // std::ifstream #include <iomanip> // std::setpercision #include <iostream> // std::cout, std::cerr, std::endl #include <limits> // std::numeric_limits #include <string> // std::string #include <vector> // std::vector namespace fs = std::filesystem; // The max size of a file stream saved into this variables constexpr auto STREAM_MAX = std::numeric_limits<std::streamsize>::max(); // The directory to the folder with all the bidders in it // What I've done here is used the a folder in the same parent // directory as this file. So we go one step out of the // current path, then go into the "bids" folder. However, // I compiled this in a different directory hierarchy, so I // commented the '.parent_path()' part out. const auto BIDDING_PATH = fs::path(fs::current_path()/*.parent_path()*/ / "bids"); /** This will be the struct we use in the vector @param name The name of the bidder @param bid The price of the bidder's bid */ struct Bidder { std::string name; double bid; // Define a constructor for std::vector::emplace_back Bidder(std::string name, double bid) : name(std::move(name)), bid(bid) {} }; std::vector<Bidder> load_bids() { std::vector<Bidder> all_bidders; // Loop through every file in the 'BIDDING_PATH' directory // (not recursively) for (auto file : fs::directory_iterator(BIDDING_PATH)) { std::ifstream cur_file(file.path().c_str()); if (cur_file.is_open()) { // Load file into a struct and add it to `all_bidders` std::string cur_name; double cur_bid; // Read the contents of the file into the above variables std::getline(cur_file, cur_name); cur_file >> cur_bid; // Now get rid of the newline character left behind by the '>>' // operator from 'cur_file >> cur_bid' cur_file.ignore(STREAM_MAX, '\n'); // Add the bidder to the `all_bidders` vector all_bidders.emplace_back(cur_name, cur_bid); // Some debugging feedback std::cout << "File loaded: " << file.path().string() << '\n' << "Bidder's name: " << all_bidders.back().name << '\n' << "Bidder's bid: " << all_bidders.back().bid << '\n' << std::endl; } else { std::cerr << "Error opening file: " << file.path().string() << std::endl; } } return all_bidders; } Bidder find_max_bidder(const std::vector<Bidder>& bidders) { // Keeps track of the winning bidder // Intially set to a null value Bidder max_bidder("", -1.0); for (const auto& cur_bidder : bidders) { if (cur_bidder.bid > max_bidder.bid) { max_bidder.name = cur_bidder.name; max_bidder.bid = cur_bidder.bid; } } // Check if no max was found if (max_bidder.bid == -1.0) { std::cerr << "Error: No max bidder was found\n" << "Are there any bidding files in the given directory?\n" << std::endl; } return max_bidder; } int main() { // Load all bidders into the `all_bidders` vector, then // calculate the max bid std::vector<Bidder> all_bidders = load_bids(); Bidder winning_bidder = find_max_bidder(all_bidders); // Print out the max bid std::cout << "The winner of this auction is " << winning_bidder.name << "!\n" << "They bid $" << winning_bidder.bid << std::setprecision(2) << "!\n" << std::endl; // Keep the console from closing std::cin.get(); return 0; }
Please note a few things:
- You need to compile this in
C++17; I used MSVC with Visual Studio 2019 - There are additional
#includes that weren't needed to explain our gameplan, but I added for formatting or making my life easier or something - You can delete the portion under "
// Some debugging feedback if you want - I did not cover the first part of your question because it (1) didn't really seem like a question and (2) you didn't seem to be having any concerns with that part
Additionally, I generated a random set of data with this Batch file:
@echo off setlocal EnableDelayedExpansion set wkdir=!cd! goto :begin :begin cd "..\bids" set rand_bid= for /l %%a in (1,1,100) do ( echo Bidder%%a > bidder%%a.txt set /a rand_bid=!random! %% 1000 echo !rand_bid!.00 >> bidder%%a.txt ) cd !wkdir! goto :end :end exit
After running that Batch file and then running my program, here was my output:
File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder1.txt Bidder's name: Bidder1 Bidder's bid: 219 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder10.txt Bidder's name: Bidder10 Bidder's bid: 693 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder100.txt Bidder's name: Bidder100 Bidder's bid: 275 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder11.txt Bidder's name: Bidder11 Bidder's bid: 669 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder12.txt Bidder's name: Bidder12 Bidder's bid: 720 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder13.txt Bidder's name: Bidder13 Bidder's bid: 741 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder14.txt Bidder's name: Bidder14 Bidder's bid: 342 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder15.txt Bidder's name: Bidder15 Bidder's bid: 124 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder16.txt Bidder's name: Bidder16 Bidder's bid: 627 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder17.txt Bidder's name: Bidder17 Bidder's bid: 244 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder18.txt Bidder's name: Bidder18 Bidder's bid: 61 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder19.txt Bidder's name: Bidder19 Bidder's bid: 79 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder2.txt Bidder's name: Bidder2 Bidder's bid: 979 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder20.txt Bidder's name: Bidder20 Bidder's bid: 211 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder21.txt Bidder's name: Bidder21 Bidder's bid: 168 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder22.txt Bidder's name: Bidder22 Bidder's bid: 44 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder23.txt Bidder's name: Bidder23 Bidder's bid: 902 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder24.txt Bidder's name: Bidder24 Bidder's bid: 753 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder25.txt Bidder's name: Bidder25 Bidder's bid: 975 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder26.txt Bidder's name: Bidder26 Bidder's bid: 220 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder27.txt Bidder's name: Bidder27 Bidder's bid: 576 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder28.txt Bidder's name: Bidder28 Bidder's bid: 541 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder29.txt Bidder's name: Bidder29 Bidder's bid: 249 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder3.txt Bidder's name: Bidder3 Bidder's bid: 788 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder30.txt Bidder's name: Bidder30 Bidder's bid: 661 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder31.txt Bidder's name: Bidder31 Bidder's bid: 98 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder32.txt Bidder's name: Bidder32 Bidder's bid: 307 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder33.txt Bidder's name: Bidder33 Bidder's bid: 698 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder34.txt Bidder's name: Bidder34 Bidder's bid: 287 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder35.txt Bidder's name: Bidder35 Bidder's bid: 489 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder36.txt Bidder's name: Bidder36 Bidder's bid: 685 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder37.txt Bidder's name: Bidder37 Bidder's bid: 196 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder38.txt Bidder's name: Bidder38 Bidder's bid: 321 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder39.txt Bidder's name: Bidder39 Bidder's bid: 332 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder4.txt Bidder's name: Bidder4 Bidder's bid: 267 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder40.txt Bidder's name: Bidder40 Bidder's bid: 593 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder41.txt Bidder's name: Bidder41 Bidder's bid: 485 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder42.txt Bidder's name: Bidder42 Bidder's bid: 863 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder43.txt Bidder's name: Bidder43 Bidder's bid: 869 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder44.txt Bidder's name: Bidder44 Bidder's bid: 612 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder45.txt Bidder's name: Bidder45 Bidder's bid: 165 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder46.txt Bidder's name: Bidder46 Bidder's bid: 889 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder47.txt Bidder's name: Bidder47 Bidder's bid: 554 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder48.txt Bidder's name: Bidder48 Bidder's bid: 783 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder49.txt Bidder's name: Bidder49 Bidder's bid: 747 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder5.txt Bidder's name: Bidder5 Bidder's bid: 966 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder50.txt Bidder's name: Bidder50 Bidder's bid: 322 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder51.txt Bidder's name: Bidder51 Bidder's bid: 775 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder52.txt Bidder's name: Bidder52 Bidder's bid: 306 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder53.txt Bidder's name: Bidder53 Bidder's bid: 376 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder54.txt Bidder's name: Bidder54 Bidder's bid: 895 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder55.txt Bidder's name: Bidder55 Bidder's bid: 374 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder56.txt Bidder's name: Bidder56 Bidder's bid: 166 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder57.txt Bidder's name: Bidder57 Bidder's bid: 332 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder58.txt Bidder's name: Bidder58 Bidder's bid: 665 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder59.txt Bidder's name: Bidder59 Bidder's bid: 177 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder6.txt Bidder's name: Bidder6 Bidder's bid: 888 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder60.txt Bidder's name: Bidder60 Bidder's bid: 399 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder61.txt Bidder's name: Bidder61 Bidder's bid: 271 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder62.txt Bidder's name: Bidder62 Bidder's bid: 996 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder63.txt Bidder's name: Bidder63 Bidder's bid: 487 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder64.txt Bidder's name: Bidder64 Bidder's bid: 874 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder65.txt Bidder's name: Bidder65 Bidder's bid: 499 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder66.txt Bidder's name: Bidder66 Bidder's bid: 72 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder67.txt Bidder's name: Bidder67 Bidder's bid: 902 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder68.txt Bidder's name: Bidder68 Bidder's bid: 66 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder69.txt Bidder's name: Bidder69 Bidder's bid: 64 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder7.txt Bidder's name: Bidder7 Bidder's bid: 246 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder70.txt Bidder's name: Bidder70 Bidder's bid: 167 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder71.txt Bidder's name: Bidder71 Bidder's bid: 961 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder72.txt Bidder's name: Bidder72 Bidder's bid: 250 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder73.txt Bidder's name: Bidder73 Bidder's bid: 280 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder74.txt Bidder's name: Bidder74 Bidder's bid: 185 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder75.txt Bidder's name: Bidder75 Bidder's bid: 962 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder76.txt Bidder's name: Bidder76 Bidder's bid: 174 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder77.txt Bidder's name: Bidder77 Bidder's bid: 157 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder78.txt Bidder's name: Bidder78 Bidder's bid: 221 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder79.txt Bidder's name: Bidder79 Bidder's bid: 312 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder8.txt Bidder's name: Bidder8 Bidder's bid: 189 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder80.txt Bidder's name: Bidder80 Bidder's bid: 842 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder81.txt Bidder's name: Bidder81 Bidder's bid: 415 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder82.txt Bidder's name: Bidder82 Bidder's bid: 313 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder83.txt Bidder's name: Bidder83 Bidder's bid: 220 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder84.txt Bidder's name: Bidder84 Bidder's bid: 200 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder85.txt Bidder's name: Bidder85 Bidder's bid: 738 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder86.txt Bidder's name: Bidder86 Bidder's bid: 323 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder87.txt Bidder's name: Bidder87 Bidder's bid: 529 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder88.txt Bidder's name: Bidder88 Bidder's bid: 196 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder89.txt Bidder's name: Bidder89 Bidder's bid: 991 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder9.txt Bidder's name: Bidder9 Bidder's bid: 917 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder90.txt Bidder's name: Bidder90 Bidder's bid: 441 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder91.txt Bidder's name: Bidder91 Bidder's bid: 691 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder92.txt Bidder's name: Bidder92 Bidder's bid: 578 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder93.txt Bidder's name: Bidder93 Bidder's bid: 234 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder94.txt Bidder's name: Bidder94 Bidder's bid: 638 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder95.txt Bidder's name: Bidder95 Bidder's bid: 569 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder96.txt Bidder's name: Bidder96 Bidder's bid: 267 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder97.txt Bidder's name: Bidder97 Bidder's bid: 788 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder98.txt Bidder's name: Bidder98 Bidder's bid: 790 File loaded: C:\Dev\C++\Others\DevBox\Testing\bids\bidder99.txt Bidder's name: Bidder99 Bidder's bid: 781 The winner of this auction is Bidder62 ! They bid $996!
I hope that helps! If you have any questions, feel free to ask!
