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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>using namespace std;int main() {const int ROW_SIZE = 2;const int COLUMN_SIZE = 5; //establish all variablesint 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;}
#include<iostream>using namespace std;const int rows = 8;const int cols = 8;char chessboard[rows][cols];void setBoard(char chessboard[][cols]);void printBoard(char chessboard[][cols]);void setBoard(char chessboard[][cols]) {for(int i = 0; i < rows; i++) {for(int j = 0; j < cols; j++) {if(i % 2 == 0 && j % 2 == 0) {chessboard[i][j] = 'x';} else {if(i % 2 != 0 && j % 2 == 1) {chessboard[i][j] = 'x';} else {chessboard[i][j] = '-';}}}}return;}void printBoard(char chessboard[][cols]) {for(int i = 0; i < rows; i++) {for(int j = 0; j < cols; j++) {cout << chessboard[i][j] << " ";}cout << endl;}return;}int main(int argc, char const *argv[]){setBoard(chessboard);printBoard(chessboard);return 0;}
#include <iostream>#include <vector>#include <utility>#include <algorithm>#include <chrono>using namespace std;#include <stdio.h>#include <Windows.h>int nScreenWidth = 120; // Console Screen Size X (columns)int nScreenHeight = 40; // Console Screen Size Y (rows)int nMapWidth = 16; // World Dimensionsint nMapHeight = 16;float fPlayerX = 14.7f; // Player Start Positionfloat fPlayerY = 5.09f;float fPlayerA = 0.0f; // Player Start Rotationfloat fFOV = 3.14159f / 4.0f; // Field of Viewfloat fDepth = 16.0f; // Maximum rendering distancefloat fSpeed = 5.0f; // Walking Speedint main(){// Create Screen Bufferwchar_t *screen = new wchar_t[nScreenWidth*nScreenHeight];HANDLE hConsole = CreateConsoleScreenBuffer(GENERIC_READ | GENERIC_WRITE, 0, NULL, CONSOLE_TEXTMODE_BUFFER, NULL);SetConsoleActiveScreenBuffer(hConsole);DWORD dwBytesWritten = 0;// Create Map of world space # = wall block, . = spacewstring map;map += L"#########.......";map += L"#...............";map += L"#.......########";map += L"#..............#";map += L"#......##......#";map += L"#......##......#";map += L"#..............#";map += L"###............#";map += L"##.............#";map += L"#......####..###";map += L"#......#.......#";map += L"#......#.......#";map += L"#..............#";map += L"#......#########";map += L"#..............#";map += L"################";auto tp1 = chrono::system_clock::now();auto tp2 = chrono::system_clock::now();while (1){// We'll need time differential per frame to calculate modification// to movement speeds, to ensure consistant movement, as ray-tracing// is non-deterministictp2 = chrono::system_clock::now();chrono::duration<float> elapsedTime = tp2 - tp1;tp1 = tp2;float fElapsedTime = elapsedTime.count();// Handle CCW Rotationif (GetAsyncKeyState((unsigned short)'A') & 0x8000)fPlayerA -= (fSpeed * 0.75f) * fElapsedTime;// Handle CW Rotationif (GetAsyncKeyState((unsigned short)'D') & 0x8000)fPlayerA += (fSpeed * 0.75f) * fElapsedTime;// Handle Forwards movement & collisionif (GetAsyncKeyState((unsigned short)'W') & 0x8000){fPlayerX += sinf(fPlayerA) * fSpeed * fElapsedTime;;fPlayerY += cosf(fPlayerA) * fSpeed * fElapsedTime;;if (map.c_str()[(int)fPlayerX * nMapWidth + (int)fPlayerY] == '#'){fPlayerX -= sinf(fPlayerA) * fSpeed * fElapsedTime;;fPlayerY -= cosf(fPlayerA) * fSpeed * fElapsedTime;;}}// Handle backwards movement & collisionif (GetAsyncKeyState((unsigned short)'S') & 0x8000){fPlayerX -= sinf(fPlayerA) * fSpeed * fElapsedTime;;fPlayerY -= cosf(fPlayerA) * fSpeed * fElapsedTime;;if (map.c_str()[(int)fPlayerX * nMapWidth + (int)fPlayerY] == '#'){fPlayerX += sinf(fPlayerA) * fSpeed * fElapsedTime;;fPlayerY += cosf(fPlayerA) * fSpeed * fElapsedTime;;}}for (int x = 0; x < nScreenWidth; x++){// For each column, calculate the projected ray angle into world spacefloat fRayAngle = (fPlayerA - fFOV/2.0f) + ((float)x / (float)nScreenWidth) * fFOV;// Find distance to wallfloat fStepSize = 0.1f; // Increment size for ray casting, decrease to increasefloat fDistanceToWall = 0.0f; // resolutionbool bHitWall = false; // Set when ray hits wall blockbool bBoundary = false; // Set when ray hits boundary between two wall blocksfloat fEyeX = sinf(fRayAngle); // Unit vector for ray in player spacefloat fEyeY = cosf(fRayAngle);// Incrementally cast ray from player, along ray angle, testing for// intersection with a blockwhile (!bHitWall && fDistanceToWall < fDepth){fDistanceToWall += fStepSize;int nTestX = (int)(fPlayerX + fEyeX * fDistanceToWall);int nTestY = (int)(fPlayerY + fEyeY * fDistanceToWall);// Test if ray is out of boundsif (nTestX < 0 || nTestX >= nMapWidth || nTestY < 0 || nTestY >= nMapHeight){bHitWall = true; // Just set distance to maximum depthfDistanceToWall = fDepth;}else{// Ray is inbounds so test to see if the ray cell is a wall blockif (map.c_str()[nTestX * nMapWidth + nTestY] == '#'){// Ray has hit wallbHitWall = true;// To highlight tile boundaries, cast a ray from each corner// of the tile, to the player. The more coincident this ray// is to the rendering ray, the closer we are to a tile// boundary, which we'll shade to add detail to the wallsvector<pair<float, float>> p;// Test each corner of hit tile, storing the distance from// the player, and the calculated dot product of the two raysfor (int tx = 0; tx < 2; tx++)for (int ty = 0; ty < 2; ty++){// Angle of corner to eyefloat vy = (float)nTestY + ty - fPlayerY;float vx = (float)nTestX + tx - fPlayerX;float d = sqrt(vx*vx + vy*vy);float dot = (fEyeX * vx / d) + (fEyeY * vy / d);p.push_back(make_pair(d, dot));}// Sort Pairs from closest to farthestsort(p.begin(), p.end(), [](const pair<float, float> &left, const pair<float, float> &right) {return left.first < right.first; });// First two/three are closest (we will never see all four)float fBound = 0.01;if (acos(p.at(0).second) < fBound) bBoundary = true;if (acos(p.at(1).second) < fBound) bBoundary = true;if (acos(p.at(2).second) < fBound) bBoundary = true;}}}// Calculate distance to ceiling and floorint nCeiling = (float)(nScreenHeight/2.0) - nScreenHeight / ((float)fDistanceToWall);int nFloor = nScreenHeight - nCeiling;// Shader walls based on distanceshort nShade = ' ';if (fDistanceToWall <= fDepth / 4.0f) nShade = 0x2588; // Very closeelse if (fDistanceToWall < fDepth / 3.0f) nShade = 0x2593;else if (fDistanceToWall < fDepth / 2.0f) nShade = 0x2592;else if (fDistanceToWall < fDepth) nShade = 0x2591;else nShade = ' '; // Too far awayif (bBoundary) nShade = ' '; // Black it outfor (int y = 0; y < nScreenHeight; y++){// Each Rowif(y <= nCeiling)screen[y*nScreenWidth + x] = ' ';else if(y > nCeiling && y <= nFloor)screen[y*nScreenWidth + x] = nShade;else // Floor{// Shade floor based on distancefloat b = 1.0f - (((float)y -nScreenHeight/2.0f) / ((float)nScreenHeight / 2.0f));if (b < 0.25) nShade = '#';else if (b < 0.5) nShade = 'x';else if (b < 0.75) nShade = '.';else if (b < 0.9) nShade = '-';else nShade = ' ';screen[y*nScreenWidth + x] = nShade;}}}// Display Statsswprintf_s(screen, 40, L"X=%3.2f, Y=%3.2f, A=%3.2f FPS=%3.2f ", fPlayerX, fPlayerY, fPlayerA, 1.0f/fElapsedTime);// Display Mapfor (int nx = 0; nx < nMapWidth; nx++)for (int ny = 0; ny < nMapWidth; ny++){screen[(ny+1)*nScreenWidth + nx] = map[ny * nMapWidth + nx];}screen[((int)fPlayerX+1) * nScreenWidth + (int)fPlayerY] = 'P';// Display Framescreen[nScreenWidth * nScreenHeight - 1] = '\0';WriteConsoleOutputCharacter(hConsole, screen, nScreenWidth * nScreenHeight, { 0,0 }, &dwBytesWritten);}return 0;}
/*Good morning! Here's your coding interview problem for today.This problem was asked by LinkedIn.A wall consists of several rows of bricks of various integer lengths and uniform height. Your goal is to find a vertical line going from the top to the bottom of the wall that cuts through the fewest number of bricks. If the line goes through the edge between two bricks, this does not count as a cut.For example, suppose the input is as follows, where values in each row represent the lengths of bricks in that row:[[3, 5, 1, 1],[2, 3, 3, 2],[5, 5],[4, 4, 2],[1, 3, 3, 3],[1, 1, 6, 1, 1]]The best we can we do here is to draw a line after the eighth brick, which will only require cutting through the bricks in the third and fifth row.Given an input consisting of brick lengths for each row such as the one above, return the fewest number of bricks that must be cut to create a vertical line.AUTHORS NOTE:Makes following assumptions:- Each row is same length- Data is in file called "data.dat" and formatted in space-separated rows- The cuts at the beginning and end of the wall are not solutionsThis requires the following file named data.dat that is a space separated file, or similar formatted file:----START FILE----3 5 1 12 3 3 25 54 4 21 3 3 31 1 6 1 1----END FILE----*/#include <algorithm>#include <iostream>#include <fstream>#include <map>#include <sstream>#include <string>#include <vector>using namespace std;int main(){vector<vector<int>> wall;ifstream in;in.open("data.dat");if(!in.good()){cout << "ERROR: File failed to open properly.\n";}/* Get input from space separated file */string line;while(!in.eof()){getline(in, line);int i;vector<int> currv;stringstream strs(line);while(strs >> i)currv.push_back(i);wall.push_back(currv);}/* Convert each value from "length of brick" to "position at end of brick" */for(int y = 0; y < wall.size(); y++){wall.at(y).pop_back(); //Delet last valfor(int x = 1; x < wall.at(y).size(); x++) //Skip the first bc data doesn't need changewall.at(y).at(x) += wall.at(y).at(x-1);}/* Check output. COMMENT OUT */// for(auto row : wall)// {// for(int pos : row)// cout << pos << " ";// cout << endl;// }/* Determine which ending position is most common, and cut there *///Exclude final position, which will be the size of the wallint mode = -1;int amt = -1;vector<int> tried;for(auto row : wall){for(int pos : row) //For each pos in the wall{//Guard. If pos is contained in the list, skip posif(find(tried.begin(), tried.end(), pos) != tried.end())continue;tried.push_back(pos);/* Cycle through each row to see if it contains the pos */int curramt = 0;for(auto currrow : wall){if( find( currrow.begin(), currrow.end(), pos ) != currrow.end() )curramt++;}//cout << pos << " " << curramt << endl;if(curramt > amt){amt = curramt;mode = pos;}}}cout << "Please cut at position " << mode << endl;cout << "This will cut through " << (wall.size() - amt) << " bricks." << endl;return 0;}
#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.}}}