## Compute Volume of Cylinder

0 likes • Nov 18, 2022
C++

## More C++ Posts

```/*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{3, 4, -1, 1}, 4) << endl;	cout << calcMissing(new int{1, 2, 0}, 3) << endl;
//No positive numbers	cout << calcMissing(new int{0}, 1) << endl;}```
```#include <iostream>using namespace std;
int main(){    cout << "Hello, World!" << endl;    return 0;}```
```#include <iostream>using namespace std;
int main() {
cout << "Hello World!\n";// Prints out "Hello World"return 0;
}```
```#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];
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[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;
int main() {

int dataEntry;    int arr;
for(int i = 0; i < 5; i++) {        cout << "Enter a number that you want to put into the array: ";        cin >> dataEntry;        arr[i] = dataEntry;    }
cout << endl;
for(int i = 0; i < 5; i++) {        cout << "Outputting array info at position " << i + 1 << ": " << arr[i] << endl;    }
for(int i=0;i<5;i++)	{				for(int j=i+1;j<5;j++)		{			if(arr[i]>arr[j])			{				int temp=arr[i];				arr[i]=arr[j];				arr[j]=temp;			}		}	}
cout << endl;
for(int i = 0; i < 5; i++) {        cout << "Outputting sorted array info at position " << i + 1 << ": " << arr[i] << endl;    }
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();      }   }}```