//We need to find out indices of vector element whose sum is matching with user input //we can return any possible pair's indices out of all possible pair // Below is code what I have written, but it fails performance criteria for large input size. Any thought to optimize this would be helpful. #include #include #include #include using namespace std; using namespace chrono; class TimeRecorder { time_point startTime; public: TimeRecorder() { startTime = high_resolution_clock::now(); } ~TimeRecorder() { time_point endTime = high_resolution_clock::now(); auto timetaken = duration_cast (endTime-startTime); cout << timetaken.count() << " micro seconds" << endl << endl; } }; pair findTwoSum(const vector& list, int sum) { int cnt = list.size(); for(int i=0;i(i,j); } } } return pair(-1,-1); } pair findTwoSum_byMap(const vector& list, int sum) { unordered_map mapValIndex; int cnt = list.size(); for(int i=0;i(itr->second,i); } else { mapValIndex.insert(pair(list[i],i)); } } return pair(-1,-1); } pair findTwoSum_byMapImproved(const vector& list, int sum) { unordered_map mapValIndex; int cnt = list.size(); for(int i=0;i(itr->second,i); } else { mapValIndex[list[i]] = i; } } return pair(-1,-1); } int main() { vector list;// = {3, 1, 5, 7, 5, 9,11,12,13,3,5,6,7,9,8,6,2,4,1,2,3,4,5,6,7,5,8,9,10,15,13,14,15,45,12,23,45,1,6,7,3,45,65,23,65,32,9,3,6,8,2,1,6,8,4,3,1,4,3,6,8,33,65}; list.reserve(10000); srand(time(nullptr)); for(int j=0;j<10000;++j) { int val = rand()%100; list.emplace_back(val); } pair indices; cout << "Brute force analysis way by vector : "; { TimeRecorder obj ; indices = findTwoSum(list, 1110); } cout << indices.first << '\n' << indices.second << endl; cout <

VectorPerformance_FindIndices