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/*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 valuefor(int i = 0; i < size; i++){if(input[i] > 0){sum += input[i];n++;}}//If no numbers higher than 0, answer is 1if(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 numberscout << calcMissing(new int[1]{0}, 1) << endl;}
#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 incrementedf.) Print "Hello, world!" then print the pointer address in hexadecimalg.) Both b and e?h.) Both c and e?i.) B, c, and e?*/// The answer is in this base 64 string:// T25seSBjLikKVGhlIGNvbXBpbGVyIGRvZXNuJ3QgYXBwcmVjaWF0ZSB5b3UgbWFraW5nIHRoZSBjaGFyYWN0ZXJzIHRoZSBwb2ludGVyIHJlZmVycyB0byBub24tY29uc3QsIGJ1dCBpdCdzIGZpbmUgd2l0aCB5b3UgY29weWluZyBhIGNvbnN0YW50IHZhbHVlLCBpLmUuIHRoZSBwb2ludGVyLCB0byBhIG5vbi1jb25zdGFudCB2YXJpYWJsZS4KSWYgeW91IHJlcGxhY2UgdGhhdCBsaW5lIHdpdGggY2hhciogY29uc3QgeWVldCA9IGNvbnN0X2Nhc3Q8Y2hhciogY29uc3Q+KGhlbGxvKTsgSXQnbGwgcHJpbnQgIkhlbGxvLCB3b3JsZCEiIHR3aWNlLCB3aGljaCBpcyB2ZXJ5IHN0cmFuZ2UgY29uc2lkZXJpbmcgdGhhdCB5ZWV0IGlzIGEgY29uc3QgcG9pbnRlciwgc28geW91J2QgdGhpbmsgaXQgd291bGQgcHJpbnQgYXMgYSBoZXhhZGVjaW1hbCBiZWNhdXNlIGlmIHlvdSB0cnkgdG8gKCsreWVldCkgd2hpbGUgbG9vcGluZyB0aHJvdWdoIHRoZSBzdHJpbmcsIHlvdSdkIGdldCBhbiBlcnJvciwgYmVjYXVzZSBpdCdzIGNvbnN0IGFuZCBjYW4ndCBiZSBjaGFuZ2VkLgpJbnN0ZWFkIG9mIHVzaW5nIGEgdGVtcGxhdGUgZnVuY3Rpb24gZm9yIG9zdHJlYW06Om9wZXJhdG9yPDwsIHRoZXkgbWFrZSBpdCBhIGZ1bmN0aW9uIHRoYXQgdGFrZXMgdHlwZSBjb25zdCBjaGFyKiwgYW5kIEMrKyBoYXMgbm8gcHJvYmxlbXMgcHJvbW90aW5nIGEgdmFyaWFibGUgdG8gY29uc3RhbnQgd2hlbiBpbXBsaWNpdCBjYXN0aW5nLCBhbmQgaXQgaGFzIG5vIHByb2JsZW1zIGltcGxpY2l0IGNhc3RpbmcgdGhlIGNvbnN0IHBvaW50ZXIgdG8gYSBub3JtYWwgcG9pbnRlciBiZWNhdXNlIGl0J3MgbWFraW5nIGEgY29weS4gVGhlIHBvaW50ZXIgZ2V0cyBjb3BpZWQgYmVjYXVzZSB0aGUgcG9pbnRlciBpcyBwYXNzZWQgYnkgdmFsdWUsIG5vdCByZWZlcmVuY2Uu
#include <iostream>using namespace std;/* Function: get_coeffParameters: double& coeff, int pos passed from bb_4acReturn: type is void so no return, but does ask for user to input data that establishes what a b and c are.*/void get_coeff(double& coeff, int pos) {char position;if(pos == 1) {position = 'a';} else if(pos == 2) { //a simple system to determine what coefficient the program is asking for.position = 'b';} else {position = 'c';}cout << "Enter the co-efficient " << position << ":"; //prompt to input coeffcoeff = 5; //input coeff}/* Function: bb_4acParameters: no parameters passed from main, but 3 params established in function, double a, b, c.Return: b * b - 4 * a * c*/double bb_4ac() {double a, b, c; //coefficients of a quadratic equationget_coeff(a, 1); // call function 1st timeget_coeff(b, 2); // call function 2nd timeget_coeff(c, 3); // call function 3rd timereturn b * b - 4 * a * c; //return b * b - 4 * a * c}int main() {cout << "Function to calculate the discriminant of the equation. . . " << endl;double determinate = bb_4ac(); //assign double determinate to bb_4ac functioncout << "The discriminant for given values is: " << determinate << endl; //output the determinate!}
#include <bits/stdc++.h>#define MAXSIZE 50000#define INF 100000using namespace std;vector<int> adj[MAXSIZE]; //Adjacency Listbool visited[MAXSIZE]; //Checks if a node is visited or not in BFS and DFSbool isConnected = true; //Checks if the input graph is connected or notint dist[MAXSIZE], discover[MAXSIZE], finish[MAXSIZE]; //Distance for BFS, in time and out time for DFSint t = 1; //Time used for DFSint u, v, i, j, k, N = 0;stack<int> st; //Stack for TopSortmultiset<pair<int, int>> s; //collection of pairs to sort by distancepair<int, int> current; //pointer variable to a position in the multisetvoid BFS(){queue<int> q; //queue for BFSq.push(1); //pushing the sourcedist[1] = 0; //assign the distance of source as 0visited[1] = 1; //marking as visitedwhile(!q.empty()){u = q.front();q.pop();for(i=0; i < adj[u].size(); i++){v = adj[u][i]; //Adjacent vertexif(!visited[v]) //if not visited, update the distance and push onto queue{visited[v] = 1;dist[v] = dist[u]+1;q.push(v);}}}for(i = 1; i <= N; i++){s.insert(make_pair(dist[i], i)); //for sorted distance}cout << "BFS results:" << endl;//prints BFS results and checks if the graph is connectedwhile(!s.empty()){current = *s.begin();s.erase(s.begin());i = current.second;j = current.first;if(j == INF) //if any infinite value, graph is not connected{cout << i << " INF" << endl;isConnected = false;}else{cout << i << " " << j << endl;}}//marks blocks of memory as visitedmemset(visited, 0, sizeof visited);}void dfsSearch(int s){visited[s] = 1; //marking it visiteddiscover[s] = t++; //assigning and incrementing timeint i, v;for(i = 0; i < adj[s].size(); i++){v = adj[s][i];if(!visited[v]) //if vertex is not visited then visit, else continue{dfsSearch(v);}}st.push(s); //pushed onto stack for TopSort if it was calledfinish[s] = t++; //out time}void DFS(){for(i = 1; i <= N; i++){if(visited[i]) //if visited continue, else visit it with DFS{continue;}dfsSearch(i); //embedded function to actually perform DFS}for(i=1;i<=N;i++){s.insert(make_pair(discover[i], i)); //minheap for sorted discovery time}cout << "DFS results:" << endl;while(!s.empty()) //Prints DFS results as long as the multiset is not empty{current = *s.begin(); //duplicates the pointer to first object in the multisets.erase(s.begin()); //erases the first object in multiseti = current.second;cout << i << " " << discover[i] << " " << finish[i] << endl; //prints discover times and finish times}}void TopSort(){//call DFS so we can have a sorted stack to printfor(i=1;i<=N;i++){if(visited[i]){continue;}dfsSearch(i);}cout<<"Topological Sort results:"<<endl;//print sorted results from DFSwhile(!st.empty()){i = st.top();st.pop();cout << i << endl;}//declare blocks of memory as visitedmemset(visited, 0, sizeof visited);}int main(){string str, num, input;int selection, connectedChoice = 0;//get to input any file, more freedom than declaring file in command linecout << "Enter the exact name of your input file [case sensitive]: ";cin >> input;ifstream inputFile(input); //Read the input file//checks if the ifstream cannot openif(inputFile.fail()){cout << endl << "No input files matching that name. Terminating..." << endl;return 0;}//Read until the end of filewhile(!inputFile.eof()){getline(inputFile, str); //read the current lineif(str == ""){continue;}if(!isdigit(str[0])) //checks to see if the first item in a line is a digit or not{cout << "Invalid file format. You have a line beginning with a non-digit. Terminating..." << endl;return 0;}stringstream ss;ss << str; //convert the line to stream of stringsss >> num; //read the line numstringstream(num) >> u;while(!ss.eof()){ss>>num;if(stringstream(num) >> v){adj[u].push_back(v); //read the adjacent vertices}}N++; //calculate the number of verticessort(adj[u].begin(), adj[u].end()); //sort the adjacency list in case it is not sorted}//creates arbitrary values for distance, will check later if INF remainfor(i = 1; i <= N; i++){dist[i] = INF;}cout << endl << "Valid Input file loaded!" << endl;while(selection != 4){cout << "************************************************" << endl;cout << "What type of analysis would you like to perform?" << endl;cout << "1: Breadth-First Search" << endl;cout << "2: Depth-First Search" << endl;cout << "3: Topological Sort" << endl;cout << "4: Quit" << endl;cout << "************************************************" << endl;//read user input and execute selectioncin >> selection;switch(selection){case 1:cout << endl;BFS();cout << endl;cout << "Would you like to know if the graph is connected?" << endl;cout << "1: Yes" << endl;cout << "Any other key: No" << endl;cin >> connectedChoice;switch(connectedChoice){case 1:if(!isConnected){cout << "The graph is not connected." << endl << endl;}else{cout << "The graph is connected!" << endl << endl;}break;default:break;}break;case 2:cout << endl;DFS();cout << endl;break;case 3:cout << endl;TopSort();cout << endl;break;case 4:return 0;default:cout << endl << "Invalid selection." << endl; //loops the selection prompt until a valid selection is input.}}}
#include "stdio.h"#include <stdlib.h>int main (int argCount, char** args) {int a = atoi(args[1]);int b = atoi(args[2]);unsigned int sum = 0;unsigned int p = 1;for (unsigned int i = 1; i < b; i++) {p = p * i;}// (b!, (1 + b)!, (2 + b)!, ..., (n + b)!)for (unsigned int i = 0; i < a; i++) {p = p * (i + b);sum = sum + p;}printf("y: %u\n", sum);return 0;}
#include <string>#include <iostream>#include "PlaylistNode.h"using namespace std;PlaylistNode::PlaylistNode() {uniqueID = "none";songName = "none";artistName = "none";songLength = 0;nextNodePtr = 0;}PlaylistNode::PlaylistNode(string uniqueID_, string songName_, string artistName_, int songLength_) {uniqueID = uniqueID_;songName = songName_;artistName = artistName_;songLength = songLength_;nextNodePtr = 0;}void PlaylistNode::InsertAfter(PlaylistNode* ptr) {this->SetNext(ptr->GetNext());ptr->SetNext(this);}void PlaylistNode::SetNext(PlaylistNode* ptr) {nextNodePtr = ptr;}string PlaylistNode::GetID() {return uniqueID;}string PlaylistNode::GetSongName() {return songName;}string PlaylistNode::GetArtistName() {return artistName;}int PlaylistNode::GetSongLength() {return songLength;}PlaylistNode* PlaylistNode::GetNext() {return nextNodePtr;}void PlaylistNode::PrintPlaylistNode() {cout << "Unique ID: " << uniqueID << endl;cout << "Song Name: " << songName << endl;cout << "Artist Name: " << artistName << endl;cout << "Song Length (in seconds): " << songLength << endl;}Playlist::Playlist() {head = tail = 0;}void Playlist::AddSong(string id, string songname, string artistname, int length) {PlaylistNode* n = new PlaylistNode(id, songname, artistname, length);if (head == 0) {head = tail = n;}else {n->InsertAfter(tail);tail = n;}}bool Playlist::RemoveSong(string id) {if (head == NULL) {cout << "Playlist is empty" << endl;return false;}PlaylistNode* curr = head;PlaylistNode* prev = NULL;while (curr != NULL) {if (curr->GetID() == id) {break;}prev = curr;curr = curr->GetNext();}if (curr == NULL) {cout << "\"" << curr->GetSongName() << "\" is not found" << endl;return false;}else {if (prev != NULL) {prev ->SetNext(curr->GetNext());}else {head = curr->GetNext();}if (tail == curr) {tail = prev;}cout << "\"" << curr->GetSongName() << "\" removed." << endl;delete curr;return true;}}bool Playlist::ChangePosition(int oldPos, int newPos) {if (head == NULL) {cout << "Playlist is empty" << endl;return false;}PlaylistNode* prev = NULL;PlaylistNode* curr = head;int pos;if (head == NULL || head == tail) {return false;}for (pos = 1; curr != NULL && pos < oldPos; pos++) {prev = curr;curr = curr->GetNext();}if (curr != NULL) {string currentSong = curr->GetSongName();if (prev == NULL) {head = curr->GetNext();}else {prev->SetNext(curr->GetNext());}if (curr == tail) {tail = prev;}PlaylistNode* curr1 = curr;prev = NULL;curr = head;for (pos = 1; curr != NULL && pos < newPos; pos++) {prev = curr;curr = curr->GetNext();}if (prev == NULL) {curr1->SetNext(head);head = curr1;}else {curr1->InsertAfter(prev);}if (curr == NULL) {tail = curr1;}cout << "\"" << currentSong << "\" moved to position " << newPos << endl;return true;}else {cout << "Song's current position is invalid" << endl;return false;}}void Playlist::SongsByArtist(string artist) {if (head == NULL) {cout << "Playlist is empty" << endl;}else {PlaylistNode* curr = head;int i = 1;while (curr != NULL) {if (curr->GetArtistName() == artist) {cout << endl << i << "." << endl;curr->PrintPlaylistNode();}curr = curr->GetNext();i++;}}}int Playlist::TotalTime() {int total = 0;PlaylistNode* curr = head;while (curr != NULL) {total += curr->GetSongLength();curr = curr->GetNext();}return total;}void Playlist::PrintList() {if (head == NULL) {cout << "Playlist is empty" << endl;}else {PlaylistNode* curr = head;int i = 1;while (curr != NULL) {cout << endl << i++ << "." << endl;curr->PrintPlaylistNode();curr = curr->GetNext();}}}