void TopK(std::vector<int> &input, int begin, int end, int k) {
int pivot = Partition(input, begin, end);
int len = pivot - begin + 1;
if (len == k)
return;
else if (len > k)
TopK(input, begin, pivot - 1, k);
else
TopK(input, pivot + 1, end, k - len);
}
void Test() {
srand(time(NULL));
int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
std::vector<int> input(a, a + 10);
std::random_shuffle(input.begin(), input.end());
std::cout << "input:";
for (int i = 0; i < input.size(); i++)
std::cout << input[i] << " ";
std::cout << std::endl;
std::vector<int> result = TopK(input, 5);
std::cout << "Output:";
for (int i = 0; i < result.size(); i++)
std::cout << result[i] << " ";
std::cout << std::endl;
std::random_shuffle(input.begin(), input.end());
std::cout << "input:";
for (int i = 0; i < input.size(); i++)
std::cout << input[i] << " ";
std::cout << std::endl;
result = TopK2(input, 5);
std::cout << "Output:";
for (int i = 0; i < result.size(); i++)
std::cout << result[i] << " ";
std::cout << std::endl;
}
void FabMapCalculator::WriteLineOfResults_SparseTopK(unsigned int nImageID)
{
//The K largest entries of the current location_probability
//get written out to file in sparse format
m_results_file << "PDF due to image " << nImageID << " :" << endl;
m_results_file << "Milliseconds to calculate: " << 1000.0*m_dfLastPDFCalculationTime << endl;
const unsigned int K = 100;
//Return the probabilities of the K most likely places
//in the format PlaceID:prob
//with PlaceID 0-based
//If there are fewer than K places, return them all
double dfReportingThreshold;
if(location_probability.size() < K)
{
dfReportingThreshold = -1.0; //Less than K places, so we want to return the probability of all places.
}
else
{
//Find the probability of the K-th most likely place.
vector<double> TopK(K);
partial_sort_copy(location_probability.begin(),location_probability.end(),TopK.begin(),TopK.end(),greater<double>());
dfReportingThreshold = TopK[K-1];
}
//Now, add to the output all places where prob is >= dfReportingThreshold, up to a maximum of K places.
vector<double> NonZeroValues;
unsigned int nReported = 0;
unsigned int max = location_probability.size();
for(unsigned int i=0;i<max;i++)
{
if(location_probability[i]>dfReportingThreshold)
{
//Add it to the output
m_results_file << i << " ";
NonZeroValues.push_back(location_probability[i]);
}
if(nReported>K)
break;
}
m_results_file << endl;
//Then write out the corresponding values.
max = NonZeroValues.size();
for(unsigned int i=0; i<max; ++i)
{
m_results_file << NonZeroValues[i] << " ";
}
m_results_file << endl;
//If data association is turned on, also record imageToPlace
#ifdef ALLOW_DATA_ASSOCIATION
m_SceneToPlace_file << m_SceneToPlace.back() << " ";
#endif
}
void TestFruitCount()
{
vector<string> fruits;
fruits.push_back("苹果");
fruits.push_back("梨");
fruits.push_back("苹果");
fruits.push_back("香蕉");
fruits.push_back("葡萄");
fruits.push_back("苹果");
fruits.push_back("苹果");
fruits.push_back("梨");
fruits.push_back("葡萄");
fruits.push_back("西瓜");
fruits.push_back("猕猴桃");
fruits.push_back("葡萄");
fruits.push_back("猕猴桃");
fruits.push_back("猕猴桃");
fruits.push_back("柠檬");
fruits.push_back("香蕉");
fruits.push_back("柚子");
fruits.push_back("香蕉");
TopK(fruits);
}
std::vector<int> TopK2(std::vector<int> &input, int k) {
TopK(input, 0, (int)input.size() - 1, k);
return std::vector<int>(input.begin(), input.begin() + k);
}
