fix bug in save model

include/LightGBM/utils/common.h

@@ -254,11 +254,25 @@ inline static std::string ArrayToString(const std::vector<T>& arr, char delimite
   return str_buf.str();
 }
 
+template<typename T>
+inline static std::string ArrayToString(const std::vector<T>& arr, size_t n, char delimiter) {
+  if (arr.empty() || n == 0) {
+    return std::string("");
+  }
+  std::stringstream str_buf;
+  str_buf << arr[0];
+  for (size_t i = 1; i < std::min(n, arr.size()); ++i) {
+    str_buf << delimiter;
+    str_buf << arr[i];
+  }
+  return str_buf.str();
+}
+
 template<typename T>
 inline static std::vector<T> StringToArray(const std::string& str, char delimiter, size_t n) {
   std::vector<std::string> strs = Split(str.c_str(), delimiter);
   if (strs.size() != n) {
-    Log::Fatal("StringToIntArray error, size doesn't match.");
+    Log::Fatal("StringToArray error, size doesn't match.");
   }
   std::vector<T> ret(n);
   if (std::is_same<T, float>::value || std::is_same<T, double>::value) {

src/io/tree.cpp

@@ -124,27 +124,27 @@ std::string Tree::ToString() {
   std::stringstream ss;
   ss << "num_leaves=" << num_leaves_ << std::endl;
   ss << "split_feature="
-    << Common::ArrayToString<int>(split_feature_real_, ' ') << std::endl;
+    << Common::ArrayToString<int>(split_feature_real_, num_leaves_ - 1, ' ') << std::endl;
   ss << "split_gain="
-    << Common::ArrayToString<double>(split_gain_, ' ') << std::endl;
+    << Common::ArrayToString<double>(split_gain_, num_leaves_ - 1, ' ') << std::endl;
   ss << "threshold="
-    << Common::ArrayToString<double>(threshold_, ' ') << std::endl;
+    << Common::ArrayToString<double>(threshold_, num_leaves_ - 1, ' ') << std::endl;
   ss << "decision_type="
-    << Common::ArrayToString<int>(Common::ArrayCast<int8_t, int>(decision_type_), ' ') << std::endl;
+    << Common::ArrayToString<int>(Common::ArrayCast<int8_t, int>(decision_type_), num_leaves_ - 1, ' ') << std::endl;
   ss << "left_child="
-    << Common::ArrayToString<int>(left_child_, ' ') << std::endl;
+    << Common::ArrayToString<int>(left_child_, num_leaves_ - 1, ' ') << std::endl;
   ss << "right_child="
-    << Common::ArrayToString<int>(right_child_, ' ') << std::endl;
+    << Common::ArrayToString<int>(right_child_, num_leaves_ - 1, ' ') << std::endl;
   ss << "leaf_parent="
-    << Common::ArrayToString<int>(leaf_parent_, ' ') << std::endl;
+    << Common::ArrayToString<int>(leaf_parent_, num_leaves_, ' ') << std::endl;
   ss << "leaf_value="
-    << Common::ArrayToString<double>(leaf_value_, ' ') << std::endl;
+    << Common::ArrayToString<double>(leaf_value_, num_leaves_, ' ') << std::endl;
   ss << "leaf_count="
-    << Common::ArrayToString<data_size_t>(leaf_count_, ' ') << std::endl;
+    << Common::ArrayToString<data_size_t>(leaf_count_, num_leaves_, ' ') << std::endl;
   ss << "internal_value="
-    << Common::ArrayToString<double>(internal_value_, ' ') << std::endl;
+    << Common::ArrayToString<double>(internal_value_, num_leaves_ - 1, ' ') << std::endl;
   ss << "internal_count="
-    << Common::ArrayToString<data_size_t>(internal_count_, ' ') << std::endl;
+    << Common::ArrayToString<data_size_t>(internal_count_, num_leaves_ - 1, ' ') << std::endl;
   ss << std::endl;
   return ss.str();
 }