From 5083bedd277a87f7f36b262a8f0e6b0e9588691b Mon Sep 17 00:00:00 2001
From: KunoiSayami <i@leanhe.dev>
Date: Mon, 25 Jul 2022 19:03:36 +0800
Subject: feat: Implement expt_0722

Signed-off-by: KunoiSayami <i@leanhe.dev>
---
 expt_0722.cpp | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 85 insertions(+), 3 deletions(-)

(limited to 'expt_0722.cpp')

diff --git a/expt_0722.cpp b/expt_0722.cpp
index 041977a..5e881b0 100644
--- a/expt_0722.cpp
+++ b/expt_0722.cpp
@@ -1,3 +1,85 @@
-//
-// Created by user on 22/07/22.
-//
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <cstdio>
+#include <iostream>
+#include <vector>
+
+constexpr size_t length = 1048576;
+std::vector<unsigned long long> population_vector, sample_vector,
+    original_vector;
+// std::vector<std::vector<unsigned long long>> result_storage;
+std::vector<bool> result_storage;
+
+long double sample_cdf(long double x) {
+  auto it = lower_bound(sample_vector.begin(), sample_vector.end(), x);
+  if (it == sample_vector.end()) {
+    return 1;
+  }
+  if (it == sample_vector.begin()) {
+    return 0;
+  }
+  auto it_prev = it - 1;
+  return ((long double)(it_prev - sample_vector.begin()) +
+          (long double)(x - *it_prev) / (*it - *it_prev)) /
+         (long double)(sample_vector.size() - 1);
+}
+
+inline long double safe_ceil(long double value) {
+  auto c = std::ceil(value);
+  return c == 0 ? 1 : c;
+}
+
+unsigned long long max_value = 0, min_value = 0xfffffffff;
+
+inline void store_into_vector(unsigned long long value) {
+  if (max_value < value) {
+    max_value = value;
+  }
+  if (min_value > value) {
+    min_value = value;
+  }
+  population_vector.push_back(value);
+}
+
+constexpr long scale_size = 10000;
+constexpr long sample_length = 1024, split_size = 1024 * scale_size;
+constexpr long test_size = 2048;
+
+int main(int argc, char const *argv[]) {
+  assert((length & 1) == 0);
+  assert(length > 1024);
+
+  FILE *file = fopen("normal_distribution.txt", "r");
+  assert(file);
+  for (long long i; fscanf(file, "%lld ", &i) != EOF; store_into_vector(i))
+    ;
+  fclose(file);
+
+  assert(population_vector.size() == length);
+
+  original_vector = population_vector;
+
+  sample_vector = std::vector<unsigned long long>(
+      original_vector.begin(), original_vector.begin() + sample_length);
+  result_storage.resize(split_size, false);
+
+  sample_vector.push_back(min_value);
+  sample_vector.push_back(max_value);
+
+  std::sort(sample_vector.begin(), sample_vector.end());
+  const auto slice_size = 1.0 / (long double)(split_size);
+
+  for (long i = 0; i < test_size; i++) {
+    auto index =
+        safe_ceil(sample_cdf(original_vector[i + sample_length]) / slice_size) -
+        1;
+    printf("%Lf\n", index);
+    auto &&item = result_storage[(int)index];
+    if (item) {
+      printf("process: %ld Fail at: %lld\n", i, original_vector[i]);
+      break;
+    }
+    item = true;
+  }
+}
\ No newline at end of file
-- 
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