[Wait for #2536][application] add generate_multiple_tokens for llm

Added generate_multiple_tokens function for first generation on llm.

This function takes one logits and generates multiple output tokens.
To meet the purpose of the target application,
even if input are multiple logits,
only the first logits is used to generate multiple output tokens.

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: Seungbaek Hong <[email protected]>

Applications/LLaMA/jni/main.cpp

@@ -219,6 +219,39 @@ std::vector<int> generate(float *logits, unsigned int NUM_VOCAB = 0,
   return outputs;
 }
 
+std::vector<int> generate_multi_tokens(
+  float *logits, unsigned int NUM_VOCAB = 0, unsigned int NUM_TARGET_TOKENS = 1,
+  float repetition_penalty = 1, unsigned int *input_ids = nullptr,
+  unsigned int NUM_INPUT_IDS = 0, unsigned int *bad_words_ids = nullptr,
+  unsigned int NUM_BAD_WORDS_IDS = 0) {
+  std::vector<int> outputs;
+  // apply repetition penalty
+  if (repetition_penalty != 1 && input_ids != nullptr && NUM_INPUT_IDS != 0) {
+    applyRepetitionPenalty(logits, input_ids, NUM_INPUT_IDS,
+                           repetition_penalty);
+  }
+
+  // apply bad words penalty
+  if (bad_words_ids != nullptr && NUM_BAD_WORDS_IDS != 0) {
+    applyBadWordsPenalty(logits, bad_words_ids, NUM_BAD_WORDS_IDS);
+  }
+
+  // Sort and generate multiple tokens
+  std::vector<std::pair<int, float>> top_indices_and_logits;
+  for (unsigned int i = 0; i < NUM_VOCAB; ++i) {
+    top_indices_and_logits.push_back({i, logits[i]});
+  }
+  sort(top_indices_and_logits.begin(), top_indices_and_logits.end(),
+       [](auto &a, auto &b) { return a.second > b.second; });
+
+  // add sampled words
+  for (unsigned int i = 0; i < NUM_TARGET_TOKENS; ++i) {
+    outputs.push_back(top_indices_and_logits[i].first);
+  }
+
+  return outputs;
+}
+
 template <typename T>
 T unwrap(std::optional<T> &&value, const std::string &error_msg) {
   if (value.has_value()) {