[C++] inclusive_scan/exclusive_scan

개요

• 현재 연산 결과가 다음 연산의 입력
• exclusive_scan는 마지막 요소는 연산에서 제외

예제

• 코드

   #include <iostream>
   #include <numeric>
   #include <vector>
      
   using namespace std;
      
   int main() {
   	vector<int> in{1, 2, 3, 4, 5};
   	vector<int> out(in.size());
      
   	inclusive_scan(begin(in), end(in), begin(out));
   	for (const auto &iter : out) {
   		cout << iter << " ";
   	}
   	cout << endl;
      
   	cout << "------ 1" << endl;
      
   	inclusive_scan(begin(in), end(in), begin(out), minus<>{});
   	for (const auto &iter : out) {
   		cout << iter << " ";
   	}
   	cout << endl;
      
   	cout << "------ 2" << endl;
      
   	inclusive_scan(begin(in), end(in), begin(out), plus<>{}, 10);
   	for (const auto &iter : out) {
   		cout << iter << " ";
   	}
   	cout << endl;
      
   	cout << "------ 3" << endl;
      
   	exclusive_scan(begin(in), end(in), begin(out), 0);
   	for (const auto &iter : out) {
   		cout << iter << " ";
   	}
   	cout << endl;
      
   	cout << "------ 4" << endl;
      
   	exclusive_scan(begin(in), end(in), begin(out), 0, minus<>{});
   	for (const auto &iter : out) {
   		cout << iter << " ";
   	}
   	cout << endl;
      
   	cout << "------ 5" << endl;
      
   	exclusive_scan(begin(in), end(in), begin(out), 10, plus<>{});
   	for (const auto &iter : out) {
   		cout << iter << " ";
   	}
   	cout << endl;
      
   	return 0;
   }
  

• 실행 결과

   1 3 6 10 15
   ------ 1
   1 -1 -4 -8 -13
   ------ 2
   11 13 16 20 25
   ------ 3
   0 1 3 6 10
   ------ 4
   0 -1 -3 -6 -10
   ------ 5
   10 11 13 16 20