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2D Array Chessboard Pattern

Nov 18, 2022AustinLeath
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More C++ Posts

Hello, World!

Nov 18, 2022AustinLeath

0 likes • 3 views

#include <iostream>
using namespace std;
int main()
{
cout << "Hello, World!" << endl;
return 0;
}

sum function

Sep 3, 2023AustinLeath

0 likes • 9 views

#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;
}

BFS/DFS/TopSort

Apr 30, 2021rlbishop99

0 likes • 3 views

#include <bits/stdc++.h>
#define MAXSIZE 50000
#define INF 100000
using namespace std;
vector<int> adj[MAXSIZE]; //Adjacency List
bool visited[MAXSIZE]; //Checks if a node is visited or not in BFS and DFS
bool isConnected = true; //Checks if the input graph is connected or not
int dist[MAXSIZE], discover[MAXSIZE], finish[MAXSIZE]; //Distance for BFS, in time and out time for DFS
int t = 1; //Time used for DFS
int u, v, i, j, k, N = 0;
stack<int> st; //Stack for TopSort
multiset<pair<int, int>> s; //collection of pairs to sort by distance
pair<int, int> current; //pointer variable to a position in the multiset
void BFS()
{
queue<int> q; //queue for BFS
q.push(1); //pushing the source
dist[1] = 0; //assign the distance of source as 0
visited[1] = 1; //marking as visited
while(!q.empty())
{
u = q.front();
q.pop();
for(i=0; i < adj[u].size(); i++)
{
v = adj[u][i]; //Adjacent vertex
if(!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 connected
while(!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 visited
memset(visited, 0, sizeof visited);
}
void dfsSearch(int s)
{
visited[s] = 1; //marking it visited
discover[s] = t++; //assigning and incrementing time
int 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 called
finish[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 multiset
s.erase(s.begin()); //erases the first object in multiset
i = 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 print
for(i=1;i<=N;i++)
{
if(visited[i])
{
continue;
}
dfsSearch(i);
}
cout<<"Topological Sort results:"<<endl;
//print sorted results from DFS
while(!st.empty())
{
i = st.top();
st.pop();
cout << i << endl;
}
//declare blocks of memory as visited
memset(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 line
cout << "Enter the exact name of your input file [case sensitive]: ";
cin >> input;
ifstream inputFile(input); //Read the input file
//checks if the ifstream cannot open
if(inputFile.fail())
{
cout << endl << "No input files matching that name. Terminating..." << endl;
return 0;
}
//Read until the end of file
while(!inputFile.eof())
{
getline(inputFile, str); //read the current line
if(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 strings
ss >> num; //read the line num
stringstream(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 vertices
sort(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 remain
for(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 selection
cin >> 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.
}
}
}

Const value const pointer question

Aug 25, 2023LeifMessinger

1 like • 11 views

#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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

Daily: Find missing array value

Aug 5, 2023usama

1 like • 5 views

/*
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;
}

Compute Volume of Cylinder

Nov 18, 2022AustinLeath

0 likes • 0 views

/*
Algorithm:
Step 1: Get radius of the cylinder from the user and store in variable r
Step 2: Get height of the cylinder from the user and store in variable h
Step 3: Multiply radius * radius * height * pi and store in v
Step 4: Display the volume
*/
#include <iostream>
using namespace std;
int main()
{
float r; //define variable for radius
float h; //define variable for height
float v;
float pi;
pi=3.1416;
cout<<"Enter radius:";
cin>>r;
cout<<"Enter height:";
cin>>h;
v=r*r*h*pi; //compute volume
cout<<"Radius:"<<r<<"\tHeight:"<<h<<endl; //display radius and height
cout<<"\n************************\n";
cout<<"Volume:"<<v<<endl;//display volume
return 0;
}