Skip to main content
Loading...

More C++ Posts

#include <iostream>
int main(){
    const char* const hello = "Hello, world!";
    
    const char* bruh = hello;
    
    char* const yeet = hello;
    
    std::cout << bruh << std::endl;
    
    std::cout << yeet << std::endl;
    
    return 0;
}

/*
    Place your bets!
    
    Will the program:
    a.) Print "Hello, world!" twice?
    b.) Compile error on line 5 (bruh initialize line) because the pointer gets implicit cast to non-const?
    c.) Compile error on line 7 (yeet initialize line) because the char gets implicit cast to non-const?
    d.) Both b and c?
    e.) Compile error line 11 (print yeet) because the pointer is constant and can't be incremented
    f.) Print "Hello, world!" then print the pointer address in hexadecimal
    g.) Both b and e?
    h.) Both c and e?
    i.) B, c, and e?
    
*/

// The answer is in this base 64 string:
// 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
//Get data file at https://codecatch.net/post.php?postID=91e87d73
//Iteration 1 of Wing Project. Solution breaks down around n=35

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <map>
using namespace std;

int getSum(map<int, int> list);
void readData(map<int, float>* data);
void lowestPrice();
void findSums(int n, vector<map<int, int>>* sumsList, map<int, float>* data);
//void findSum(map<int, int> currList, int x, int n, vector<map<int, int>>* sumsList);
void findSum(map<int, int> currList, int x, int n, vector<map<int, int>>* sumsList, map<int, float>* data);
float getPrice(map<int, int> set, map<int, float>* data);

template <typename S>
ostream& operator<<(ostream& os, const vector<S>& vector)
{
	// Printing all the elements using <<
	for (auto element : vector) {
	os << element << " ";
	}
	return os;
}

bool operator==(map<int, int> m1, map<int, int> m2)
{
	if(m1.size() != m2.size())
	return false;

	bool ret = true;

	for(auto it = m1.begin(); it !=m1.end() && ret; it++)
	{
	if(ret && m1.count(it->first) != m2.count(it->first))
	ret = false;

	if(ret && m1.count(it->first) == 1)
	{
	if(m1.at(it->first) != m2.at(it->first))
	ret = false;
	}
	}

	return ret;
}


int main()
{
	map<int, float> data;
	readData(&data);

	vector<map<int, int>> *sumsList;
	sumsList = new vector<map<int, int>>;
	findSums(40, sumsList, &data);

	for(auto el : *sumsList)
	{
	for(auto it = el.begin(); it != el.end(); it++)
	{
	cout << it->first << "->" << it->second << " ";
	}
	cout << getPrice(el, &data) << endl;
	}

	return 0;
}

/* Returns the price of wings given a set of numbers of wings to buy.
	* Returns -1 if the set contains a number that is not possible to buy.
	*/
float getPrice(map<int, int> set, map<int, float>* data)
{
	float price = 0;
	for(auto it = set.begin(); it != set.end(); it++)
	{
	//If data doesn't contain an element of set, return -1
	if(data->count(it->first) == 0)
	return -1;
	
	price += data->at(it->first) * it->second; //pricePerPacket * qtyOfPackets
	}

	return price;
}

/* Adds the elements of list.
	* Suppose mapping is <num, qty>.
	* Returns sum(num*qty)
	*/
int getSum(map<int, int> list)
{
	int sum = 0;
	for(auto it = list.begin(); it != list.end(); it++)
	sum += it->first * it->second;
	return sum;
}

void findSums(int n, vector<map<int, int>>* sumsList, map<int, float>* data)
{
	map<int, int> currList;

	//Recur when currSum < n
	auto it = data->begin();
	while(it->first <= n && it != data->end())
	{
	findSum(currList, it->first, n, sumsList, data);
	it++;
	}
}

void findSum(map<int, int> currList, int x, int n, vector<map<int, int>>* sumsList, map<int, float>* data)
{
	//Append x to currList
	if(currList.count(x) == 0)
	currList.emplace(x, 1);
	else
	{
	int val = 1+ currList.at(x);
	currList.erase(x);
	currList.emplace(x, val);
	}

	//Determine current sum, check for return cases
	int currSum = getSum(currList);

	if(currSum > n)
	return;
	else if(currSum == n)
	{

	//Check to make sure no duplicates
	for(auto list : *sumsList)
	{
	if(list == currList)
	return;
	}

	sumsList->push_back(currList);
	return;
	}

	//Recur when currSum < n
	auto it = data->begin();
	while(it->first <= n-x && it != data->end())
	{
	findSum(currList, it->first, n, sumsList, data);
	it++;
	}
}

void readData(map<int, float>* data)
{
	ifstream file ("./data", ifstream::in);

	if(file.is_open())
	{
	int i = 0;
	while(!file.eof())
	{
	float wings, price;
	string skipnl;
	file >> wings;
	file >> price;

	data->emplace(wings, price);

	getline(file, skipnl);
	i++;
	}
	}
}
#include <iostream>
#include <vector>
#include <limits>

#define DEBUG_TRIAL false

class Trial{
    public:
        const size_t HEIGHT;
        std::string record;
        
        //Breaking height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.
        //Eggs is the eggs remaining.
        //Start is the bottom floor.
        //End is one above the top floor.
        const size_t BREAKING_HEIGHT;
        size_t eggs;
        size_t start;
        size_t end;
        
        
        size_t floorsLeft(){
            return (end-start);
        }
        
        size_t middle(){
            return start + (floorsLeft()/2UL);
        }
        
        size_t drops = 0;
        Trial(const size_t BREAKING_HEIGHT, size_t eggs, size_t start, size_t end): BREAKING_HEIGHT(BREAKING_HEIGHT), eggs(eggs), start(start), end(end), HEIGHT(end), record(end, '_'){
            record[BREAKING_HEIGHT] = 'B'; //Marking the breaking point
        }
        
        bool foundAnswer(){
            return ((record[0] == 'X') || (record.find("OX")!=std::string::npos));
        }
        
        //returns true if the egg broke.
        //height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.
        bool drop(size_t height){
            
            #if DEBUG_TRIAL
                std::cout << "Start: " << start << ". End: " << end << ". Floors Left: " << floorsLeft() << ". Middle Index: " << middle() << std::endl;
            #endif
            
            drops++;
            bool cracked = height >= BREAKING_HEIGHT;
            if(cracked) --eggs;
            
            //Update the record
            record[height] = (height >= BREAKING_HEIGHT)? 'X' : 'O';
            
            #if DEBUG_TRIAL
                //Print the record
                std::cout << record << std::endl;
            #endif
        
            return cracked;
        }
        
        size_t nowWhat(){
            if(foundAnswer()){
                return drops;
            }else if(eggs <= 0){ //Ran out of eggs
                throw "Algorithm failed! No more eggs!";
                return 1UL;
            }else if(eggs > 1){
                return wrecklessSearch();
            }else{
                return safeSearch();
            }
        }
        
        size_t safeSearch(){
            if(drop(start)){
                --end;
            }else{
                ++start;
            }
            
            return nowWhat();
        }
        
        size_t wrecklessSearch(){
            //If the egg breaks
            if(drop(middle())){
                end -= (floorsLeft()/2UL);
            }else{ //egg doesn't crack
                start += (floorsLeft()/2UL);
            }
            
            return nowWhat();
        }
        
        //returns the amount of drops needed to find the answer
        size_t search(){
            return nowWhat();
        }
};

//Height is the height of the building in floors.
//Breaking height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.
//Eggs is the eggs given.
//returns the amount of drops needed to find the answer
size_t search(const size_t height, const size_t BREAKING_HEIGHT, size_t eggs){
    Trial trial(BREAKING_HEIGHT, eggs, 0, height);
    return trial.search();
}

class TrialStats {
    public:
        size_t min = std::numeric_limits<size_t>::max();
        size_t max = 0;
        double mean = -1.0;
        
        void printStats(){
            // Print the results
            std::cout << "Minimum drops: " << min << std::endl;
            std::cout << "Maximum drops: " << max << std::endl;
            std::cout << "Mean drops: " << mean << std::endl;
        }
};

//Benchmarks all the possible breaking points of a single building height with a number of eggs.
TrialStats trial(const size_t HEIGHT, const size_t eggs){
    
    TrialStats stats;
    int totaldrops = 0;

    //Test every possible breaking point
    //Breaking height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.
    for (int breakingHeight = 0; breakingHeight < HEIGHT; ++breakingHeight) {
        size_t drops = search(HEIGHT, breakingHeight, eggs);

        stats.min = std::min(stats.min, drops);
        stats.max = std::max(stats.max, drops);
        totaldrops += drops;
    }

    // Calculate the mean number of drops
    stats.mean = static_cast<double>(totaldrops) / HEIGHT;
    
    return stats;
}

//Benchmarks a single building height from 1 egg to MAX_EGGS
void testTower(const size_t height, const size_t MAX_EGGS){
    //Drop every amount of eggs that you'd need.
    for (int eggs = 1; eggs <= MAX_EGGS; ++eggs) {
        std::cout << "Building height: " << height << ". Num eggs: " << eggs << std::endl;
        
        TrialStats stats = trial(height, eggs);
        stats.printStats();
        
        std::cout << std::endl << std::endl;
    }
}

//Benchmarks all buildings from 0 to MAX_HEIGHT
void benchmark(const size_t MAX_HEIGHT){
    const size_t MAX_EGGS = 2;
    //Test every building
    for (size_t height = 1; height <= MAX_HEIGHT; ++height) {
        testTower(height, std::min(height, MAX_EGGS));
    }
}

int main() {
    constexpr size_t MAX_HEIGHT = 36;
    
    benchmark(MAX_HEIGHT);

    return 0;
}