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i have a sort of this :
say for eg: a[1] has has a list of elements...Code:vector < vector <int > >a(100);
I have defined t priority queue stl to hold vector of elemnts..
But on a single push i need all the elemts of 1..ie a[1] to be stored in the priority queue
something like thisi need all the elemts of 1 to be pushed at once...Code:Q.push(a[1])
The above doesnt work...it says
any suggestionsQuote:
No matching.....bla bla bla
>> i have a sort of this :
Well it "sort of" matters what *exactly* you have.
>> The above doesnt work...it says "No matching.....bla bla bla"
That just means that you've passed it the wrong...whatchyamacallit.
>> any suggestions
Sure: Don't ask such vague questions.
I did exactly what i asked..The question was not vague...i gave with an example. and snippet...Quote:
Originally Posted by Sebastiani
My question is not answered
That bla bla bla is pretty important to diagnose your problem. The compilers emit messages for a reason, so you read them, understand what's wrong and fix the error.Quote:
No matching.....bla bla bla
Compiles for me. So you haven't provided enough context.Code:#include <vector>
#include <queue>
int main()
{
std::vector<std::vector<int> > v(100);
std::priority_queue<std::vector<int> > pq;
pq.push(v[1]);
}
So do you want the vector stored in a[1] to get pushed into the priority queue to or do you want the elements in the vector to get pushed? Your question is very vague and I think you might not realize that you're dealing with a vector of a vector of ints, rather than a single vector. To visualize your:This means that you have a 2-dimensional matrix of integers. If you want to push the integers themselves you'll need to loop through each vector individually.Code:vector < vector <int > >a(100);
This code made me think. How does priority_queue compare elements?Quote:
Originally Posted by anon
prints 13 for me. I was wondering if it just looked at the first element of the vector. What exactly is happening? I see it uses a template functionCode:#include <vector>
#include <iostream>
#include <queue>
int main()
{
std::vector<std::vector<int> > v;
std::vector<int> temp;
temp.push_back(3);
temp.push_back(7);
temp.push_back(2);
v.push_back(temp);
temp.clear();
temp.push_back(13);
temp.push_back(17);
temp.push_back(12);
v.push_back(temp);
std::priority_queue<std::vector<int> > pq;
pq.push(v[0]);
pq.push(v[1]);
std::cout << pq.top()[0] << std::endl;
}
but what is Container::value_type?Code:class Compare = less<typename Container::value_type>
Container::value_type is pretty clearly std::vector<int>. Operator < is defined for any standard vector, using lexicographical_compare.Quote:
Originally Posted by linuxdude