Lookup tables v4

labs/bad_speculation/lookup_tables_1/solution.cpp

@@ -1,48 +1,29 @@
 #include "solution.hpp"
 
+int bucket_map[151] = {
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0-12
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 13-28
+  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // 29-40
+  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,// 41-52
+  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, // 53-70
+  5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, // 71-82
+  6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, // 83-99
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // 100-109
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 
+  7
+};
+
 static std::size_t mapToBucket(std::size_t v) {
-                              //   size of a bucket
-  if      (v < 13)  return 0; //   13
-  else if (v < 29)  return 1; //   16
-  else if (v < 41)  return 2; //   12
-  else if (v < 53)  return 3; //   12
-  else if (v < 71)  return 4; //   18
-  else if (v < 83)  return 5; //   12
-  else if (v < 100) return 6; //   17
-  return DEFAULT_BUCKET;
+  return bucket_map[v];
 }
 
 std::array<std::size_t, NUM_BUCKETS> histogram(const std::vector<int> &values) {
   std::array<std::size_t, NUM_BUCKETS> retBuckets{0};
-  std::array<std::size_t, 151> bucket_map;
-
-  for (int i = 0; i < 13; ++i) {
-    bucket_map[i] = 0;
-  }
-  for (int i = 13; i < 29; ++i) {
-    bucket_map[i] = 1;
-  }
-  for (int i = 29; i < 41; ++i) {
-    bucket_map[i] = 2;
-  }
-  for (int i = 41; i < 53; ++i) {
-    bucket_map[i] = 3;
-  }
-  for (int i = 53; i < 71; ++i) {
-    bucket_map[i] = 4;
-  }
-  for (int i = 71; i < 83; ++i) {
-    bucket_map[i] = 5;
-  }
-  for (int i = 83; i < 100; ++i) {
-    bucket_map[i] = 6;
-  }
-
-  for (int i = 100; i <= 150; ++i) {
-    bucket_map[i] = DEFAULT_BUCKET;
-  }
   for (auto v : values) {
-    retBuckets[bucket_map[v]]++;
+    retBuckets[mapToBucket(v)]++;
   }
   return retBuckets;
 }