how to iterate through a vector of type std: :pair

Question

i have a vector
std: :vector<std::pair<int,int>> k;

how could i iterate through this vector. k. begin is giving error. Although k. begin->first is giving correct value. but i want to iterate through all elements, how could i do this.

Answer 1

You would iterate through it like any other vector.

Either by using an iterator of the correct type (e.g std::vector<std::pair<int,int>>::iterator)

or a range based loop with the auto keyword.

See: https://www.sololearn.com/learn/261/?ref=app for more info

Here is an example:
https://code.sololearn.com/cDOYsqXbSQQb/?ref=app

Note: I have used const iterators as no values are to be changed in the example code I provided.

This document may also assist in your understanding of iteration/iterators

https://www.cprogramming.com/tutorial/stl/iterators.html

Answer 2

NOTE : pair and vector are 2 different things.

Pair is a container just like vector is.
You need to use this class methods..
Take a pair singularly..
std::pair<T,U> myPair; //T and U can be same type

myPair.makepair(a,b); //a single pair
c=myPair.first;
d=myPair.second;
Pair<int,int> pairArray[5];
....

vector<pair<int,int>> myV;
for (int i = 0 .....)
myV.push_back(make_pair(arr1[i],arr2[I]));

for (int i ... )
cout<< myV[i].first << '-' << myV[i].second;

Answer 3

https://code.sololearn.com/cx5t4kFdf4pW/?ref=app