Question

//trendtracker.h
#ifndef TRENDTRACKER_H
#define TRENDTRACKER_H

#include <vector>
#include <string>

using namespace std;

class Trendtracker
{

public:
   Trendtracker();
  

void insert(string ht);

   int size();

  
   void tweeted(string ht);

   int popularity(string name);

   string top_trend();

   void top_three_trends(vector<string> &T);

   void top_k_trends(vector<string> &T, int k);

private:

   class Entry
   {
   public:
       string hashtag;
       int pop;
   };

vector<Entry> E;
};

#endif

//trendtracker.cpp

#include"trendtracker.h"
using namespace std;

// Creates a new Trendtracker tracking no hashtags.
//
// Must run in O(1) time.
Trendtracker::Trendtracker(){

}

// Inserts a hashtag (tweeted 0 times) into the Trendtracker.
// If the hashtag already is in Trendtracker, does nothing.
//
// Must run in O(n) time.
void Trendtracker::insert(string ht){
   Entry t;
   int n = E.size();
   t.hashtag = ht;
   t.pop = 0;
  
   for (int i = 0; i < n; i++) {
       if (ht == E[i].hashtag) {
           break;
       }
   }
}

// Return the number of hashtags in the Trendtracker.
//
// Must run in O(1) time.
int Trendtracker::size(){
   return E.size();
}

// Adds 1 to the total number times a hashtag has been tweeted.
// If the hashtag does not exist in TrendTracker, does nothing.
//
// Must run in O(n) time.
void Trendtracker::tweeted(string ht) {
   int n = E.size();
   for (int i = 0; i < n; i++) {
       if (E[i].hashtag == ht) {
           E[i].pop++;
       }
   }
}

// Returns the number of times a hashtag has been tweeted.
// If the hashtag does not exist in Trendtracker, returns -1.
//
// Must run in O(n) time.
int Trendtracker::popularity(string name){
   int i = 0;
   int n = E.size();
   bool check = 0;

   for (int i = 0; i < n; i++) {
       if (name == E[i].hashtag) {
           check = 1;
       }
   }

   if (check == 1) {
       return E[i].pop;
   }
   else {
       return -1;
   }
}

// Returns a most-tweeted hashtag.
// If the Trendtracker has no hashtags, returns "".
//
// Must run in O(n) time.
string Trendtracker::top_trend(){
   if (E.size() == 0) {
       return "";
   }
  
   int popular;
   for (int i = 0, n = E.size(), popular = 0; i < n; i++) {
       if (E[i].pop > E[popular].pop) {
           popular = i;
       }
   }
   return E[popular].hashtag;

}

// Fills the provided vector with the 3 most-tweeted hashtags,
// in order from most-tweeted to least-tweeted.
//
// If there are fewer than 3 hashtags, then the vector is filled
// with all hashtags (in most-tweeted to least-tweeted order).
//
// Must run in O(n) time.
void Trendtracker::top_three_trends(vector<string> &T){
  
   int f, s, t;
   int n = E.size();
   for (int i = 0, f = s = t = n; i < n; i++) {
       if (E[i].pop > E[f].pop) {
           t = s;
           s = f;
           f = i;
       }
       else if (E[i].pop > E[s].pop) {
           t = s;
           s = i;
       }
       else if(E[i].pop > E[t].pop) {
           t = i;
       }
   }

   T.push_back(E[f].hashtag);
   if (s != n && s != f)
       T.push_back(E[s].hashtag);
   if (t != n && t != s)
       T.push_back(E[t].hashtag);
  
}

// Fills the provided vector with the k most-tweeted hashtags,
// in order from most-tweeted to least-tweeted.
//
// If there are fewer than k hashtags, then the vector is filled
// with all hashtags (in most-tweeted to least-tweeted order).
//
// Must run in O(nk) time.
void Trendtracker::top_k_trends(vector<string> &T, int k){}

can you help me figure out how to solve whatever code i dont have completed in trendtracker.cpp

Answer 1

Try this code for trendtracker

#include "trendtracker.h"
Trendtracker::Trendtracker(string filename){
ifstream myFile;
myFile.open(filename);
string tag;
  

if(myFile.fail()){
cerr << "Error opening file" << endl;
exit(1);
}
  
while( myFile >> tag){
Entry e;
e.hashtag = tag;
e.pop = 0;
E.push_back(e);
}
  
  
myFile.close();
}

// Return the number of hashtags in the Trendtracker.
//
// Must run in O(1) time.
int Trendtracker::size(){
  
return static_cast<int>(E.size());
}

// Adds 1 to the total number times a hashtag has been tweeted.
// If the hashtag does not exist in TrendTracker, does nothing.
//
// Must run in O(log(n)) time.
void Trendtracker::tweeted(string ht){

//uses the index that search returns to access the given hashtag and increase its popularity
E[search(ht)].pop++;
  
//check for duplicates
bool duplicate = false;
for(int i = 0; i < S.size(); i++){
if(S[i] == search(ht))
duplicate = true;
}
if(!duplicate)
S.push_back(search(ht));
  
  
//sort the elements of S by the pops in the entrys they refer to(from large to small)
  
//insertion sort
for(int i = 0; i < S.size(); i++){
int j = i;
while(j > 0 && E[S[j]].pop > E[S[j-1]].pop){
int temp = S[j-1];
S[j-1] = S[j];
S[j] = temp;
j--;
}
}
  
//if s has more than 3 elements, remove the last one
if(S.size() > 3)
S.pop_back();
  
//printS();
}

// Returns the number of times a hashtag has been tweeted.
// If the hashtag does not exist in Trendtracker, returns -1.
//
// Must run in O(log(n)) time.
int Trendtracker::popularity(string name){
if(search(name) != -1)
return E[search(name)].pop;
return -1;
}

// Returns a most-tweeted hashtag.
// If the Trendtracker has no hashtags, returns "".
//
// Must run in O(1) time.

string Trendtracker:: top_trend(){
if(E.size() == 0)
return "";
return E[S[0]].hashtag;

}

// Fills the provided vector with the 3 most-tweeted hashtags,
// in order from most-tweeted to least-tweeted.
//
// If there are fewer than 3 hashtags, then the vector is filled
// with all hashtags (in most-tweeted to least-tweeted order).
//
// Must run in O(1) time.

void Trendtracker::top_three_trends(vector<string> &T){
T.clear();

if(E.size() == 1) //test case for tiny.txt
T.push_back(E[0].hashtag);
else{
if(S.size() == 0){
T.push_back(E[0].hashtag);
T.push_back(E[1].hashtag);
T.push_back(E[1].hashtag);
}
else if(S.size() == 1){
T.push_back(E[S[0]].hashtag);
T.push_back(E[1].hashtag);
T.push_back(E[2].hashtag);
}
else if(S.size() == 2){
T.push_back(E[S[0]].hashtag);
T.push_back(E[S[1]].hashtag);
T.push_back(E[2].hashtag);

}else if(S.size() == 3){
T.push_back(E[S[0]].hashtag);
T.push_back(E[S[1]].hashtag);
T.push_back(E[S[2]].hashtag);
}
}
  
}

// Optional helper method.
// Returns the index of E containing an Entry with hashtag ht.
// If no such hashtag is found, returns -1.
//
// Should run in O(log(n)).
int Trendtracker::search(string ht){
int low = 0;
int high = E.size() - 1;
  
while(low <= high){
int mid = ((high + low)/2);
  
if(E[mid].hashtag < ht)
low = mid + 1;
else if(E[mid].hashtag > ht)
high = mid - 1;
else
return mid; //found
  
}
  
return -1;
}