/**
 This program demonstrates how to use dependent async tasks to create
 algorithm tasks.
*/

#include <taskflow/taskflow.hpp>
#include <taskflow/algorithm/for_each.hpp>
#include <taskflow/algorithm/transform.hpp>
#include <taskflow/algorithm/reduce.hpp>

int main(){

 const size_t N = 65536;

 tf::Executor executor;
 
 int sum{1};
 std::vector<int> data(N);

 // for-each
 tf::AsyncTask A = executor.silent_dependent_async(tf::make_for_each_task(
 data.begin(), data.end(), [](int& i){ i = 1; }
 ));

 // transform
 tf::AsyncTask B = executor.silent_dependent_async(tf::make_transform_task(
 data.begin(), data.end(), data.begin(), [](int& i) { return i*2; }
 ), A);

 // reduce
 tf::AsyncTask C = executor.silent_dependent_async(tf::make_reduce_task(
 data.begin(), data.end(), sum, std::plus<int>{}
 ), B);
 
 // wait for all async task to complete
 executor.wait_for_all();
 
 // verify the result
 if(sum != N*2 + 1) {
 throw std::runtime_error("INCORRECT RESULT");
 }
 else {
 std::cout << "CORRECT RESULT\n";
 }
 
 return 0;
}