binary heap of user classes
May 8, 2022 at 5:50pm UTC
Hi, I'm trying to print out a binary max heap, that is made up of classes that I've created above but nothing is printing out.
I've tried playing with how I print and how stuff gets inserted into the class and nothing has worked so far, so I'm open to ideas!
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
// range heap example
#include <iostream> // std::cout
#include <algorithm> // std::make_heap, std::pop_heap, std::push_heap, std::sort_heap
#include <vector> // std::vector
#include <fstream>
#include <bits/stdc++.h>
#include<sstream>
using namespace std;
class name_t {
public :
string first;
string last;
name_t(){
string first = "" ;
string last = "" ;
name = first + last;
}
bool operator <(const name_t &rhs) const {
return this ->last < rhs.last;
}
void print() const {
string fullname = last + ", " + first;
if (fullname.length() < 21){
while (fullname.length() != 21){
fullname = fullname + "." ;
}
}
cout << fullname;
}
private :
static int w;
string name;
};
int name_t::w = 0;
class scores_t {
public :
int sum;
int realMean;
scores_t(){
int sum = 0;
int realMean = 0;
}
bool operator <(const scores_t &rhs) const {
return this ->realMean < rhs.realMean;
}
void insert(int k){
scores.push_back(k);
}
void insert_done(){
sum = accumulate(scores.begin(), scores.end(), 0.0);
realMean = sum / scores.size();
}
void print(){
for (unsigned int i = 0; i < scores.size(); i++){
cout << setw(3) << scores.at(i) << " " ;
}
cout << ": " << realMean;
cout << endl;
}
private :
vector<int > scores;
float mean;
};
class namescores_t {
public :
bool operator <(const namescores_t &rhs) const {
if (this ->scores.realMean < rhs.scores.realMean){
return true ;
}
if (this ->scores.realMean == rhs.scores.realMean){
if (this ->name.last < rhs.name.last){
return true ;
}
}
return false ;
}
void print_name(){
name.print();
}
void print_scores(){
scores.print();
}
public :
name_t name;
scores_t scores;
};
int main (int argc, char * argv[]) {
fstream fin;
if (argc !=3){
cout << "usage incorrect" ;
return -1;
}
int k = atoi(argv[1]);
fin.open(argv[2]);
vector<namescores_t> v;
if (fin.is_open()){
while (true ){
name_t n;
scores_t s;
if (fin.eof()) break ;
string tmp;
getline(fin, tmp);
stringstream ss(tmp);
ss >> n.first;
ss >> n.last;
int tmpScore;
while (ss >> tmpScore){
int realScore;
realScore = tmpScore;
s.insert(realScore);
}
s.insert_done();
namescores_t t;
t.name = n;
t.scores = s;
v.push_back(t);
}
}
fin.close();
make_heap(v.begin(), v.end());
vector<namescores_t>::iterator it;
for (it = v.begin(); it != v.end() && !v.empty(); ++it){
it->print_name();
it->print_name();
}
return 0;
}
May 8, 2022 at 7:16pm UTC
May 8, 2022 at 7:27pm UTC
George you put me into an infinite loop! Help!
(Okay let's just agree to use this thread)
May 9, 2022 at 1:06am UTC
Not that is really matters to me one way or the other, but......
...since a binary heap construct is likely to not be something for a really truly beginner I'd simply opine the discussion should be done in the general forum thread.
Beyond that I'm opinion-less.
May 9, 2022 at 8:27am UTC
@SSDEEZ,
Just as a matter of interest ... what is your code supposed to do?
May 9, 2022 at 8:43am UTC
Is the file data being read correctly? Has it opened ok? What's the format of the data file? Please provide a sample for testing.
Reading the file looks wrong - as .eof() is set when attempting to read - not after a read has completed. getline() would usually be the while condition.
May 9, 2022 at 9:32am UTC
Without having proper test data, I've tried to deduce the format. Perhaps something like this which reads and processes the data without using heap:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115
#include <iostream>
#include <algorithm>
#include <vector>
#include <fstream>
#include <numeric>
#include <iomanip>
struct name_t {
std::string first;
std::string last;
name_t() = default ;
bool operator <(const name_t& rhs) const {
return last < rhs.last;
}
void print() const {
std::string fullname {last + ", " + first};
if (fullname.length() < 21)
fullname += std::string(21 - fullname.size(), '.' );
std::cout << fullname;
}
};
class scores_t {
public :
double sum {};
double realMean {};
scores_t() = default ;
bool operator <(const scores_t& rhs) const {
return realMean < rhs.realMean;
}
void insert(double k) {
scores.push_back(k);
}
void insert_done() {
sum = std::accumulate(scores.begin(), scores.end(), 0.0);
realMean = sum / scores.size();
}
void print() const {
for (unsigned int i {}; i < scores.size(); ++i)
std::cout << std::setw(3) << std::fixed << std::setprecision(1) << scores.at(i) << " " ;
std::cout << ": " << realMean << '\n' ;
}
private :
std::vector<double > scores;
};
class namescores_t {
public :
namescores_t(const name_t& n, const scores_t& s) : name(n), scores(s) {}
bool operator <(const namescores_t& rhs) const {
if (scores.realMean < rhs.scores.realMean)
return true ;
if (scores.realMean == rhs.scores.realMean)
if (name.last < rhs.name.last)
return true ;
return false ;
}
void print_name() const {
name.print();
}
void print_scores() const {
scores.print();
}
public :
name_t name;
scores_t scores;
};
int main(int argc, char * argv[]) {
if (argc != 3) {
std::cout << "usage incorrect\n" ;
return -1;
}
std::fstream fin(argv[2]);
if (!fin)
return (std::cout << "Cannot open file\n" ), 1;
std::vector<namescores_t> v;
for (name_t n; fin >> n.first >> n.last; ) {
scores_t s;
for (double tmpScore; fin >> tmpScore; s.insert(tmpScore));
fin.clear();
s.insert_done();
v.emplace_back(n, s);
}
//make_heap(v.begin(), v.end());
for (const auto & e : v) {
e.print_name();
e.print_scores();
}
}
Using data file:
Ronald Jones
7.5 8.8 7 8.1 8 9.8 9.3 8.9 9.1 9
Mirabella Jones
6.5 9.8 6 7.1 8 8.8 6.3 7.9 9.1 8
Ryan Sheckler
8.5 7.8 6 9.1 7 8.8 7.3 9.9 8.1 7
displays:
Jones, Ronald........7.5 8.8 7.0 8.1 8.0 9.8 9.3 8.9 9.1 9.0 : 8.6
Jones, Mirabella.....6.5 9.8 6.0 7.1 8.0 8.8 6.3 7.9 9.1 8.0 : 7.8
Sheckler, Ryan.......8.5 7.8 6.0 9.1 7.0 8.8 7.3 9.9 8.1 7.0 : 8.0
Last edited on May 9, 2022 at 9:36am UTC
May 9, 2022 at 3:00pm UTC
@lastchance its supposed to take a text file of scores and print them out in decreasing order based on their score averages. That's why I wanted to use a heap.
May 9, 2022 at 3:18pm UTC
What does the input text file look like, and why do you need three separate classes?
A single "Person" class with data members lastname, firstname, averageScore would be sufficient to put through std::sort.
May 9, 2022 at 3:39pm UTC
print them out in decreasing order based on their score averages.
OK. In my code above replace L109 with:
std::sort(v.begin(), v.end(), [](const auto & a, const auto & b) { return a.scores.realMean > b.scores.realMean; });
which now displays:
Jones, Ronald........7.5 8.8 7.0 8.1 8.0 9.8 9.3 8.9 9.1 9.0 : 8.6
Sheckler, Ryan.......8.5 7.8 6.0 9.1 7.0 8.8 7.3 9.9 8.1 7.0 : 8.0
Jones, Mirabella.....6.5 9.8 6.0 7.1 8.0 8.8 6.3 7.9 9.1 8.0 : 7.8
May 9, 2022 at 3:43pm UTC
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
#include <iostream>
#include <algorithm>
#include <vector>
#include <fstream>
#include <sstream>
#include <string>
using namespace std;
struct Person
{
string firstname, lastname;
double averageScore;
};
istream & operator >> ( istream &in, Person &person )
{
string line;
getline( in, line );
stringstream ss( line );
ss >> person.firstname >> person.lastname;
int n = 0;
double sum = 0;
for ( double value; ss >> value; n++ ) sum += value;
person.averageScore = sum / n;
return in;
}
bool compScore( const Person &p, const Person &q )
{
if ( p.averageScore != q.averageScore ) return p.averageScore > q.averageScore;
if ( p.lastname != q.lastname ) return p.lastname > q.lastname;
return p.firstname > q.firstname;
}
int main()
{
// ifstream in( "input.txt" );
istringstream in( "Josef Stalin 1.4 1.7 2.2 0.5\n"
"Volodymyr Zelensky 9.1 9.9 9.8 9.6\n"
"Vladimir Putin 0.4 0.3 0.1 0\n" );
vector<Person> people;
for ( Person p; in >> p; ) people.push_back( p );
sort( people.begin(), people.end(), compScore );
for ( Person &p : people ) cout << p.firstname << " " << p.lastname << ": " << p.averageScore << '\n' ;
}
Volodymyr Zelensky: 9.6
Josef Stalin: 1.45
Vladimir Putin: 0.2
Last edited on May 9, 2022 at 3:46pm UTC
May 9, 2022 at 6:10pm UTC
@lastchance yeah, a single class would be much easier, alas professors these days like to have their way.
last time I'll take a class for this stuff at a uni
May 10, 2022 at 8:10am UTC
a single class would be much easier
Not really. Not in this case. You essentially have "one class". It just happens to have members that have members. A composite structure.
If you had separate arrays that you had to reorder simultaneously -- that would be more a chore.
[EDIT]
Looking at your
operator< definitions creates an impression that you don't have a clue of what you are doing -- you don't exploit the encapsulation that the multiple classes offer.
Last edited on May 10, 2022 at 1:05pm UTC
Topic archived. No new replies allowed.