How to write a vector with a pair of ints as key and int as value in c++?

I am new to programming, just started learning hashing.
I tried to find out - like map - how can we assign a pair of ints as key and an int as value in a vector.

On searching i did find vector of pair where first element of pair is key and second element of pair as value but i need a way to make "pair of int" as KEY and an int as VALUE.

I felt a need of this as i needed to sort a pair of int with respect to their value. Any suggestion?