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Critques

0 likes • Feb 4, 2021
C++
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SAM 5 words with bitmaps

ThiccDaddyLOAF
0 likes • Oct 23, 2022
C++
//Leif Messinger
//Finds all sets of 5 5 letter words that don't have duplicate letters in either themselves or each other.
//First it reads the words in and puts them in groups of their bitmasks
//After that, we recurse on each group. Before doing that, we remove the group from the set of other groups to check it against.
#include <cstdio> //getchar, printf
#include <cassert> //assert
#include <vector>
#include <set>
#include <algorithm> //std::copy_if
#include <iterator> //std::back_inserter
#define CHECK_FOR_CRLF true
#define MIN_WORDS 5
#define MAX_WORDS 5
#define WORD_TOO_LONG(len) (len != 5)
const unsigned int charToBitmask(const char bruh){
assert(bruh >= 'a' && bruh <= 'z');
return (1 << (bruh - 'a'));
}
void printBitmask(unsigned int bitmask){
char start = 'a';
while(bitmask != 0){
if(bitmask & 1){
putchar(start);
}
bitmask >>= 1;
++start;
}
}
//Pointer needs to be deleted
const std::set<unsigned int>* getBitmasks(){
std::set<unsigned int>* bitmasksPointer = new std::set<unsigned int>;
std::set<unsigned int>& bitmasks = (*bitmasksPointer);
unsigned int bitmask = 0;
unsigned int wordLength = 0;
bool duplicateLetters = false;
for(char c = getchar(); c >= 0; c = getchar()){
if(CHECK_FOR_CRLF && c == '\r'){
continue;
}
if(c == '\n'){
if(!(WORD_TOO_LONG(wordLength) || duplicateLetters)) bitmasks.insert(bitmask);
bitmask = 0;
wordLength = 0;
duplicateLetters = false;
continue;
}
if((bitmask & charToBitmask(c)) != 0) duplicateLetters = true;
bitmask |= charToBitmask(c);
++wordLength;
}
return bitmasksPointer;
}
void printBitmasks(const std::vector<unsigned int>& bitmasks){
for(unsigned int bruh : bitmasks){
printBitmask(bruh);
putchar(','); putchar(' ');
}
puts("");
}
//Just to be clear, when I mean "word", I mean a group of words with the same letters.
void recurse(std::vector<unsigned int>& oldBitmasks, std::vector<unsigned int> history, const unsigned int currentBitmask){
//If there's not enough words left
if(oldBitmasks.size() + (-(history.size())) + (-MIN_WORDS) <= 0){
//If there's enough words
if(history.size() >= MIN_WORDS){
//Print the list
printBitmasks(history);
}
return;
//To make it faster, we can stop it after 5 words too
}else if(history.size() >= MAX_WORDS){
//Print the list
printBitmasks(history);
return;
}
//Thin out the array with only stuff that matches the currentBitmask.
std::vector<unsigned int> newBitmasks;
std::copy_if(oldBitmasks.begin(), oldBitmasks.end(), std::back_inserter(newBitmasks), [&currentBitmask](unsigned int bruh){
return (bruh & currentBitmask) == 0;
});
while(newBitmasks.size() > 0){
//I know this modifies 'oldBitmasks' too. It's intentional.
//This makes it so that the word is never involved in any of the child serches or any of the later searches in this while loop.
const unsigned int word = newBitmasks.back(); newBitmasks.pop_back();
std::vector<unsigned int> newHistory = history;
newHistory.push_back(word);
recurse(newBitmasks, newHistory, currentBitmask | word);
}
}
int main(){
const std::set<unsigned int>* bitmasksSet = getBitmasks();
std::vector<unsigned int> bitmasks(bitmasksSet->begin(), bitmasksSet->end());
delete bitmasksSet;
recurse(bitmasks, std::vector<unsigned int>(), 0);
return 0;
}

Daily: Find missing array value

aedrarian
0 likes • Dec 24, 2021
C++
/*
Good morning! Here's your coding interview problem for today.
This problem was asked by Stripe.
Given an array of integers, find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can contain duplicates and negative numbers as well.
For example, the input [3, 4, -1, 1] should give 2. The input [1, 2, 0] should give 3.
You can modify the input array in-place.
*/
#include <iostream>
using namespace std;
int calcMissing(int* input, int size)
{
int sum = 0;
int n = 1; //add one to account for missing value
for(int i = 0; i < size; i++)
{
if(input[i] > 0)
{
sum += input[i];
n++;
}
}
//If no numbers higher than 0, answer is 1
if(sum == 0)
return 1;
return (n*(n+1)/2) - sum; //Formula is expectedSum - actualSum
/* expectedSum = n*(n+1)/2, the formula for sum(1, n) */
}
int main()
{
cout << calcMissing(new int[4]{3, 4, -1, 1}, 4) << endl;
cout << calcMissing(new int[3]{1, 2, 0}, 3) << endl;
//No positive numbers
cout << calcMissing(new int[1]{0}, 1) << endl;
}

C++ SigFigs

ThiccDaddyLOAF
0 likes • Sep 7, 2022
C++
#include <iostream>
#include <cstring>
int main(int argc, char** argv){
//With decimal
if(strstr(argv[1], ".") != nullptr){
int i = 0;
//Skip i to first non 0 digit
while(argv[1][i] < '1' || argv[1][i] > '9') ++i;
//If digit comes before decimal
if((argv[1] + i) < strstr(argv[1], ".")){ //Good example of pointer arithmetic
std::cout << strlen(argv[1] + i) - 1 << std::endl; //Another good example
}else{
//If digit is after decimal
std::cout << strlen(argv[1] + i) << std::endl;
}
}else{
//Without decimal
int m = 0;
int i = 0;
while(argv[1][i] < '1' || argv[1][i] > '9') ++i; //In case of some number like 0045
for(; argv[1][i] != '\0'; ++i){
if(argv[1][i] >= '1' && argv[1][i] <= '9') m = i + 1;
}
std::cout << m << std::endl;
}
return 0;
}

Hash Table Example

AustinLeath
0 likes • Nov 18, 2022
C++
using namespace std;
class Hash
{
int BUCKET; // No. of buckets
// Pointer to an array containing buckets
list<int> *table;
public:
Hash(int V); // Constructor
// inserts a key into hash table
void insertItem(int x);
// deletes a key from hash table
void deleteItem(int key);
// hash function to map values to key
int hashFunction(int x) {
return (x % BUCKET);
}
void displayHash();
};
Hash::Hash(int b)
{
this->BUCKET = b;
table = new list<int>[BUCKET];
}
void Hash::insertItem(int key)
{
int index = hashFunction(key);
table[index].push_back(key);
}
void Hash::deleteItem(int key)
{
// get the hash index of key
int index = hashFunction(key);
// find the key in (inex)th list
list <int> :: iterator i;
for (i = table[index].begin();
i != table[index].end(); i++) {
if (*i == key)
break;
}
// if key is found in hash table, remove it
if (i != table[index].end())
table[index].erase(i);
}
// function to display hash table
void Hash::displayHash() {
for (int i = 0; i < BUCKET; i++) {
cout << i;
for (auto x : table[i])
cout << " --> " << x;
cout << endl;
}
}
// Driver program
int main()
{
// array that contains keys to be mapped
int a[] = {15, 11, 27, 8, 12};
int n = sizeof(a)/sizeof(a[0]);
// insert the keys into the hash table
Hash h(7); // 7 is count of buckets in
// hash table
for (int i = 0; i < n; i++)
h.insertItem(a[i]);
// delete 12 from hash table
h.deleteItem(12);
// display the Hash table
h.displayHash();
return 0;
}

minimum matrix values

AustinLeath
0 likes • Nov 18, 2022
C++
#include <iostream>
using namespace std;
int main() {
const int ROW_SIZE = 2;
const int COLUMN_SIZE = 5; //establish all variables
int matrix[ROW_SIZE][COLUMN_SIZE];
int minVal;
for (int i = 0; i < ROW_SIZE; ++i) // for loop to ask user to enter data.
{
for (int h = 0; h < COLUMN_SIZE; ++h) {
cout << "Enter data for row #" << i + 1 << " and column #" << h + 1 << ": ";
cin >> matrix[i][h];
}
}
cout << "You entered: " << endl;
for (int i = 0; i < ROW_SIZE; ++i) //for statements to output the array neatly
{
for (int h = 0; h < COLUMN_SIZE; ++h) {
cout << matrix[i][h] << "\t";
}
cout << endl;
}
cout << "Minimum for each row is: {";
for (int i = 0; i < ROW_SIZE; i++) //for statements to find the minimum in each row
{
minVal = matrix[i][0];
for (int h = 0; h < COLUMN_SIZE; h++) {
if (matrix[i][h] < minVal) // if matrix[i][h] < minVal -> minVal = matrix[i][h];
{
minVal = matrix[i][h];
}
}
cout << minVal << ", ";
}
cout << "}" << endl;
cout << "Minimum for each column is: {";
for (int i = 0; i < COLUMN_SIZE; i++) //for statements to find the minimum in each column
{
minVal = matrix[0][i];
for (int h = 0; h < ROW_SIZE; h++) {
if (matrix[h][i] < minVal) //replaces minVal with array index for that column that is lowest
{
minVal = matrix[h][i];
}
}
cout << minVal << ", ";
}
cout << "}" << endl;
return 0;
}

Stock Options Analyzer

AustinLeath
0 likes • Nov 18, 2022
C++
#include <iostream>
#include <cmath>
#include <string.h>
using namespace std;
int main() {
string tickerName;
int numOfContracts;
float currentOptionValue;
cout << "Enter a stock ticker: ";
getline(cin, tickerName);
cout << "Enter the current number of " << tickerName << " contracts you are holding: ";
cin >> numOfContracts;
cout << "Enter the current price of the option: ";
cin >> currentOptionValue;
cout << "The value of your " << tickerName << " options are: $" << (currentOptionValue * 100.00) * (numOfContracts);
cout << endl;
return 0;
}