feat(exp): Add stddev output

Signed-off-by: KunoiSayami <[email protected]>

1 files changed, 24 insertions, 1 deletions

diff --git a/exp_0702.cpp b/exp_0702.cpp
index c767afd..b848b67 100644
--- a/exp_0702.cpp
+++ b/exp_0702.cpp
@@ -2,6 +2,7 @@
 #include <cassert>
 #include <cmath>
 #include <cstdio>
+#include <numeric>
 #include <vector>
 
 constexpr size_t length = 1048576;
@@ -29,6 +30,28 @@ inline long double safe_ceil(long double value) {
   return c == 0 ? 1 : c;
 }
 
+long double calc_stddev() {
+  std::vector<size_t> elements;
+  std::vector<long double> tmp_vector;
+  for (auto &element : result_storage) {
+    elements.push_back(element.size());
+  }
+  tmp_vector.resize(elements.size());
+  // auto sum = std::accumulate(elements.begin(),
+  // elements.end(),decltype(elements)::value_type(0)); size_t sum = length;
+  // printf("\nsum: %ld\n", sum);
+  // auto mu = sum / (long double)elements.size();
+  long double mu = sample_length;
+  // printf("mu: %Lf\n", mu);
+
+  std::transform(elements.begin(), elements.end(), tmp_vector.begin(),
+                 [&mu](size_t element) { return std::pow(element - mu, 2); });
+
+  return std::sqrt(std::accumulate(tmp_vector.begin(), tmp_vector.end(),
+                                   decltype(tmp_vector)::value_type(0)) /
+                   elements.size());
+}
+
 int main() {
   assert((length & 1) == 0);
   assert(length > 1024);
@@ -65,5 +88,5 @@ int main() {
   for (const auto &element : result_storage) {
     printf("%ld ", element.size());
   }
-  puts("");
+  printf("%Lf\n", calc_stddev());
 }
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