Function argmin

tensorflow/contrib/tensor_forest/kernels/v4/grow_stats.cc:624–634

// https://pdfs.semanticscholar.org/72f1/5aba2e67b1cc9cd1fb12c99e101c4c1aae4b.pdf

int argmin(const std::unordered_map<int, float>& m) {
  int c = -1;
  float f = FLT_MAX;
  for (const auto it : m) {
    if (it.second < f) {
      f = it.second;
      c = it.first;
    }
  }
  return c;
}

void FixedSizeClassStats::accumulate(int c, float w) {
  auto it = class_weights_.find(c);