set of pairs in c++ with st.begin() code example
Example: find in set of pairs using first value cpp
auto it = std::find_if(st.begin(), st.end(), [](const pair<int,int>& p ){ return p.first == 1; });
auto it = std::find_if(st.begin(), st.end(), [](const pair<int,int>& p ){ return p.first == 1; });