C++ How to find pair of 3 integers in vector< pair<int, pair<int, int> > >

Question

For example, I store 3 elements simultaneously like:

vector< pair<int, pair<int, int> > > myvec; myvec.push_back(make_pair(1, make_pair(2, 3))); How can I check if {1,2,3} exist (as a pair) in myvec?

Answer 1

You can use find() from algorithm .

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    
    vector< pair<int, pair<int, int> > > myvec;  
    auto p = make_pair(1, make_pair(2, 3));
    myvec.push_back(p);
    
    if ( std::find(myvec.begin(), myvec.end(), p) != myvec.end() )
        cout << "Found";
    else
        cout << "Not Found";
    return 0;
}

Answer 2

sure, you can do this:

 for (auto mval: myvec) {
   if (mval.first == 1 && mval.second.first == 2 && mval.second.second == 3)
     cout << "Found" << endl;
 }

or this:

typedef pair<int,int> IntPair;
typedef pair<int, IntPair> MyPair;
 
...
for (auto mval: myvec) {
   if (mval == MyPair(1, IntPair(2, 3)))
     cout << "Found" << endl;
 }

or a few other ways.