【DL 7周年抽奖活动】GiveawayWinnersGenerator

GiveawayWinnersGenerator.cpp

#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <ctime>
#include <cstdlib>

using namespace std;


bool ReadFileLines(char* fileName, vector<string> &results);
void PrintAllNames(vector<string> nickNames);
int GetRandomNumber(int min, int max);
void GetWinners(int prizes, vector<string> nickNames);



int main(int argc, char* argv[])
{
	if(argc != 2)
	{
		cout << "Please directly drag the name list txt into this exe file!" << endl;
		
		system("pause");
		
		return 1;
	}
	
	vector<string> nickNames = {};
	
	if(!ReadFileLines(argv[1], nickNames))
	{
		system("pause");
		
		return 1;
	}
	
	
	PrintAllNames(nickNames);
	
	cout << endl << "Number of prizes: ";
	 
	int prizes = 0;
	cin >> prizes;
	
	
	GetWinners(prizes, nickNames);
	
	system("pause");
	
	return 0;
}


bool ReadFileLines(char* fileName, vector<string> &results)
{
	ifstream file(fileName);
	
    if (!file.is_open()) 
	{
        cout << "Error: Unable to open file: " <<fileName << endl;
        return false;
    }
    
    string line = "";
    
    while (getline(file, line)) {
        results.push_back(line);
    }
    
    file.close();
    
    return true;
}

void PrintAllNames(vector<string> nickNames)
{
	cout << "====== Participants ======" << endl;
	int size = nickNames.size();
	
	for(int i = 0; i < size; i++)
	{
		cout << nickNames[i] << endl;
	}
}

static bool seeded = false;

int GetRandomNumber(int min, int max)
{
	if(!seeded)
	{
		unsigned seed = time(0);
		srand(seed);
		seeded = true;
	}
	
	
	int range = max - min;
	return (rand() % range) + min;
	
}


void GetWinners(int prizes, vector<string> nickNames)
{
	int size = nickNames.size();
	
	prizes = min(prizes, size);
	
	
	cout << "====== Winners ======" << endl;
	
	if(prizes < 1)
	{
		cout << "No Winners";
		return;
	}
	
	
	for(int i = 1; i <= prizes; i++)
	{
		
		
		if(size <= 0)
		{
			break;
		}
		
		
		int currentRollWinner = GetRandomNumber(0, size);
		
		
		cout << "[" << i << "] " << nickNames[currentRollWinner] << endl;
		
		nickNames.erase(nickNames.begin() + currentRollWinner);
		
		size --;
	}
}