cdsa

 auto unionGroups = [&](int a, int b, int time) {
            int rootA = find(a);
            int rootB = find(b);

            if (rootA != rootB) {
                // If one component is infected, propagate the infection time to the other component
                if (infectionTime[rootA] != -1 && infectionTime[rootB] == -1 && !vaccinated[rootB]) {
                    infectionTime[rootB] = time; // Set infection time for rootB
                } else if (infectionTime[rootB] != -1 && infectionTime[rootA] == -1 && !vaccinated[rootA]) {
                    infectionTime[rootA] = time; // Set infection time for rootA
                }

                // Merge groups by rank
                if (rank[rootA] > rank[rootB]) {
                    parent[rootB] = rootA;
                } else if (rank[rootA] < rank[rootB]) {
                    parent[rootA] = rootB;
                } else {
                    parent[rootB] = rootA;
                    rank[rootA]++;
                }
            }
        };