#include <iostream>#include <vector>using namespace std;template <typename T>static void Swap(T* data, int index1, int index2){if (index1 == index2)return;T temp = *(data + index1);*(data + index1) = *(data + index2);*(data + index2) = temp;}template <typename T, typename GreaterThanFunc>static int Partition(T* data, int left, int right, GreaterThanFunc greaterThanFunc){T& ref = data[right];int lastSmallerThanRefIndex = left - 1;for (int i = left; i < right; ++i){if (greaterThanFunc(ref, *(data + i))){++lastSmallerThanRefIndex;Swap(data, lastSmallerThanRefIndex, i);}}++lastSmallerThanRefIndex;Swap(data, lastSmallerThanRefIndex, right);return lastSmallerThanRefIndex;}template <typename T, typename GreaterThanFunc>static void QuickSort(T* data, int left, int right, GreaterThanFunc greaterThanFunc){if (left >= right)return;if ((right - left) == 1){if ((*(data + left)) > (*(data + right)))Swap(data, left, right);return;}int mid = Partition(data, left, right, greaterThanFunc);QuickSort(data, left, mid - 1, greaterThanFunc);QuickSort(data, mid + 1, right, greaterThanFunc);}template <typename T>class Comparer{public:bool operator()(const T& a, const T& b){return (a > b);}};struct CrossPair{public:CrossPair(int x, int y) : m_X(x), m_Y(y) {}CrossPair(int x) : m_X(x), m_Y(-1) {}void Display(){cout << m_X;if (m_Y > 0)cout << ' ' << m_Y;cout << endl;}private:int m_X;int m_Y;};static int CrossBridge(int* people, int cnt, vector<CrossPair>& crossPairs){if (cnt == 0)return 0;if (cnt == 1){crossPairs.push_back(CrossPair(people[0]));return people[0];}if (cnt == 2){crossPairs.push_back(CrossPair(people[0], people[1]));return people[1];}if (cnt == 3){crossPairs.push_back(CrossPair(people[0], people[2]));crossPairs.push_back(CrossPair(people[0]));crossPairs.push_back(CrossPair(people[0], people[1]));return people[0] + people[1] + people[2];}if (cnt == 3){crossPairs.push_back(CrossPair(people[0], people[2]));crossPairs.push_back(CrossPair(people[0]));crossPairs.push_back(CrossPair(people[0], people[1]));return people[0] + people[1] + people[2];}if ((people[0] + people[cnt - 2]) > (2 * people[1])){crossPairs.push_back(CrossPair(people[0], people[1]));crossPairs.push_back(CrossPair(people[0]));crossPairs.push_back(CrossPair(people[cnt - 2], people[cnt - 1]));crossPairs.push_back(CrossPair(people[1]));return people[1] * 2 + people[0] + people[cnt - 1] + CrossBridge(people, cnt - 2, crossPairs);}else{crossPairs.push_back(CrossPair(people[0], people[cnt - 1]));crossPairs.push_back(CrossPair(people[0]));crossPairs.push_back(CrossPair(people[0], people[cnt - 2]));crossPairs.push_back(CrossPair(people[0]));return people[0] * 2 + people[cnt - 2] + people[cnt - 1] + CrossBridge(people, cnt - 2, crossPairs);}}static void RunTestCase(){int cnt;cin >> cnt;if (cnt <= 0){cout << 0 << endl;return;}int* people = new int[cnt];for (int i = 0; i < cnt; ++i)cin >> people[i];QuickSort(people, 0, cnt - 1, Comparer<int>());vector<CrossPair> crossPairs;int time = CrossBridge(people, cnt, crossPairs);cout << time << endl;for (size_t i = 0; i < crossPairs.size(); ++i)crossPairs[i].Display();delete[] people;}static void Test(){int testCnt;cin >> testCnt;for (int i = 0; i < testCnt; ++i){RunTestCase();if (i < (testCnt - 1))cout << endl;}}int main(int argc, char* argv[]){Test();return 0;}
