編集履歴

回答編集履歴

修正

2018/02/16 00:29

投稿

スコア16614

test CHANGED Viewed

@@ -18,15 +18,13 @@
 std::tuple<double,double,double>
-statistics(InputIterator first, InputIterator last) {
+statistics(InputIterator first, size_t n) {
-  size_t n = std::distance(first, last);
-  double sum = std::accumulate(first, last, 0.0);
+  double sum = std::accumulate(first, std::next(first,n), 0.0);
   double mean = sum / n;
-  double stddev = sqrt(std::inner_product(first, last, first, 0.0)/n - mean*mean);
+  double stddev = sqrt(std::inner_product(first, std::next(first,n), first, 0.0)/n - mean*mean);
   return { sum, mean, stddev };
@@ -48,11 +46,11 @@
   using namespace std;
-  auto input = { 0.01, 0.02, 0.03, 0.04, 0.05  };
+  double input[] = { 0.01, 0.02, 0.03, 0.04, 0.05  };
   double sum, mean, stddev;
-  tie(sum, mean,stddev) = statistics(begin(input), end(input));
+  tie(sum, mean, stddev) = statistics(input, 5);
   cout << "sum = " << sum << "\n"