CODEWITHSUNDEEP
c++algorithmc++11stl
theandroid
theandroid

Reputation: 71

How to find an element which is between a pair in the set of pairs?

set<pair<int,int> >s;
pair<int,int>a0 = make_pair(1,10); // pair is kind of range of integer
air<int,int>a1 = make_pair(11,50);
s.insert(a0);
s.insert(a1);

Now I need a function which returns true when I search any integer which lies between range of any pair in the set.

Upvotes: 3

Views: 1252

Answers (3)

max66
max66

Reputation: 66230

Now I need a function which returns true when I search any integer which lies between range of any pair in the set.

It seems a work for std::any_of()

#include <set>
#include <utility>
#include <iostream>
#include <algorithm>

bool anyRange (std::set<std::pair<int, int>> const & s, int v)
 { return std::any_of(s.cbegin(), s.cend(),
                      [&](std::pair<int, int> const & p)
                       { return (p.first <= v) && (v <= p.second); }); }

int main()
 {
   std::set<std::pair<int, int>> s { {1, 10}, {11, 50} };

   std::cout << anyRange(s, -5) << std::endl; // print 0
   std::cout << anyRange(s, 5)  << std::endl; // print 1
   std::cout << anyRange(s, 25) << std::endl; // print 1
   std::cout << anyRange(s, 75) << std::endl; // print 0
 }

Upvotes: 2

XZ6H
XZ6H

Reputation: 1789

Iterate over the set and check if the integer is in each pair inside the set

bool bet(set<pair<int,int> > s, int integer) 
{
    for (auto it : s)
    {
        if (it.first <= integer && it.second >= integer) 
            return true;
    }
    return false;
}

Upvotes: 2

Laney
Laney

Reputation: 1649

If you want fast search (i.e. better than linear) then you should use interval tree. std::set is not suitable for this problem

Upvotes: 1

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