Dijkstra algoriithim

#1

sir how can I the sorting in the set of pair to be according the second parameter?
I have used a custom class like:
set<pair<T,int>, compare>s; —>(the compiler gives me error message)
so what is the solution?

#2

hello @mzk1994

u need to make functor for custom comparision and then pass its name in the second argument of the set.
example->

struct CustomCompare   //declaring functor, u can use class also  
{
    bool operator()(const int& lhs, const int& rhs)
    {
        return lhs < rhs;
    }

    bool operator()(const Person& lhs, const Person& rhs)
    {
        return lhs.getAge() < rhs.getAge();
    }
};

// and then u can pass it in ur set as->
 set<Person,CustomCompare> setOfPersons;

    setOfPersons.insert(Person("Person 1", 25));
    setOfPersons.insert(Person("Person 2", 16));
    setOfPersons.insert(Person("Person 3", 28));
    setOfPersons.insert(Person("Person 4", 9));

    for(set<Person,CustomCompare>::iterator it = setOfPersons.begin(); it!=setOfPersons.end(); ++it)
    {
        cout << it->getName() << " , age : " << it->getAge()<< endl;
    }
#3

template
class compare{
public:
bool operator()(const pair<T,int>&p1,const pair<T,int>&p2)const{
return p2.second>p1.second;
}
};
template
void graph::dijkstra(T src){
unordered_map<T,int>dist;
for(auto node:hashmap)
dist[node.first]=INT_MAX;
dist[src]=0;
set<pair<T,int>,compare>s;
}

what is the problem !!!
why the compiler gives me error about set
I want to make the comparison based on second parameter

#4

@mzk1994

pls save the complete code in cb ide , and then share its link with me

#5

how could reach cb ide?

#6

go to this link -> https://ide.codingblocks.com/
paste complete code in the editor
and then press ctrl +s and then save

a url will be generated , share that url with me

#7

I saved it, then how can I share it with you?

#8

…

when u click on save button , a url will be generated in ur search bar , share that url with me (in reply).

#9

do you recieved any thing?

#10

…

no ,
u will get url something like this-> https://ide.codingblocks.com/s/461099
in ur search bar.
copy that url and paste here

#11

Coding Blocks IDE

#12

u have made a genereic functor.
so while passing it in set , u need to mention the datatype as well.

for example->

set<pair<T,int>,Compare<int> > s;

or  for any other dataype use its name
set<pair<T,int>,Compare< DatatypeNaME > > s;
#13

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