/**
 * @file mix_cc/algorithm/nearest_index.h
 * @brief 找到容器内与元素值最相近的索引,无需容器有序
 * @author Cat (null.null.null@qq.com)
 * @version 0.1
 * @date 2021-07-06
 * 找到容器内与元素值最相近的索引
 * Company: Baosight Co. Ltd.
 * DO NOT COPY/USE WITHOUT PERMISSION
 *
 */

#pragma once
#include <algorithm>
#include <cstddef>
#include <limits>
#include <queue>
#include <vector>

namespace mix_cc {
/**
 * @brief 找到容器内与元素值最相近的索引,无需容器有序
 * @tparam Tp
 * @tparam Container
 * @param  seq              序列容器
 * @param  values           元素
 * @return std::vector<size_t>
 */
template <typename Tp, typename Container>
std::vector<size_t> nearset_index(Container seq,
                                  std::initializer_list<Tp> values) {
  std::vector<Tp> mins(values.size(), std::numeric_limits<Tp>::max());
  std::vector<size_t> index(values.size(), seq.size() - 1);
  int i = 0;
  int j = 0;
  for (auto x : seq) {
    auto diff = fabs(x - *(values.begin() + i));
    if (diff <= mins[i]) {
      mins[i] = diff;
      j++;
    } else {
      if (i < values.size()) {
        index[i] = j;
        i++;
      }
      if (i == values.size()) {
        return index;
      }
    }
  }
  return index;
}
}  // namespace mix_cc