Test

#include <iostream>

using namespace std;

typedef unsigned short us;

void check_connectivity(us* indexTriples, int* connectivityOut, int all_verticies, pair<us, us> p, int index, int shift) {
    if(p.first > p.second) {
        swap(p.first, p.second);
    }
    for(int j = 0; j < all_verticies; j += 3) {
        if(j == index) continue;
        int first = indexTriples[j];
        int second = indexTriples[j + 1];
        int third = indexTriples[j + 2];
        if((p.first == first && p.second == second) || (p.first == second && p.second == first)) {
            connectivityOut[index + shift] = j;
            break;
        }
        if((p.first == second && p.second == third) || (p.first == third && p.second == second)) {
            connectivityOut[index + shift] = j + 1;
            break;
        }
        if((p.first == third && p.second == first) || (p.first == first && p.second == third)) {
            connectivityOut[index + shift] = j + 2;
        }
    }
}

void findConnectivity(us* indexTriples, int T, int* connectivityOut) {
    const int all_verticies = 3 * T;
    std::fill(connectivityOut, connectivityOut + all_verticies, -1);
    for(int i = 0; i < all_verticies; i += 3) {
        pair<us, us> p1 = make_pair(indexTriples[i], indexTriples[i + 1]);
        pair<us, us> p2 = make_pair(indexTriples[i + 1], indexTriples[i + 2]);
        pair<us, us> p3 = make_pair(indexTriples[i + 2], indexTriples[i]);

        check_connectivity(indexTriples, connectivityOut, all_verticies, p1, i, 0);
        check_connectivity(indexTriples, connectivityOut, all_verticies, p2, i, 1);
        check_connectivity(indexTriples, connectivityOut, all_verticies, p3, i, 2);
    }
}


int main()
{
    int T = 3;
    int* connectivityOut = new int[3 * T];
    us *input = new us[9] {0,2,7,1,7,2,6,2,0};
    findConnectivity(input, 3, connectivityOut);
    for(int i = 0; i < 3 * T; ++i) {
        cout << connectivityOut[i] + 1 << ' ';
    }
}