/**
 * @author Parikshit Ram (pram@cc.gatech.edu)
 * @file math_functions.h
 *
 * This file has certain functions that find the 
 * highest or lowest element in an array or 
 * in a row of a matrix and returns them
 *
 */
 
#include "fastlib/fastlib.h"
#include "fastlib/fastlib_int.h"


/**
 * Finds the index of the minimum element
 * in each row of a matrix
 *
 * Example use:
 * @code
 * Matrix& mat;
 * index_t indices[mat.n_rows()];
 *
 * ...
 * 
 * min_element(mat, indices);
 * @endcode
 */

void min_element(Matrix& element, index_t *indices) {
	
  index_t last = element.n_cols() - 1;
  index_t first, lowest;
  index_t i;
	
  for (i = 0; i < element.n_rows(); i++) {
		
    first = lowest = 0;
    if (first == last) {
      indices[i] = last;
    }
    while (++first <= last) {
      if (element.get(i, first) < element.get(i, lowest)) {
	lowest = first;
      }
    }
    indices[i] = lowest;
  }
  return;
}

/**
 * Returns the index of the maximum element
 * in a float array 'array' of length 'length'.
 *
 * Example use:
 * @code
 * index_t length, index;
 * float array[length];
 * ...
 * index = max_element_index(array, length);
 * @endcode
 */
int max_element_index(float *array, int length) {
  
  int last = length - 1;
  int first = 0;
  int highest = 0;
	
  if (first == last) {
    return last;
  }
  while (++first <= last) {
    if (array[first] > array[highest]) {
      highest = first;
    }
  }
  return highest;
}

/**
 * Finds the index of the maximum element in an arraylist
 * of floats
 *
 * Example use:
 * @code
 * index_t index;
 * ArrayList<float> array;
 * ...
 * index = max_element_index(array);
 * @endcode
 */
int max_element_index(ArrayList<float>& array){

  int last = array.size() - 1;
  int first = 0;
  int highest = 0;

  if (first == last) {
    return last;
  }
  while (++first <= last) {
    if (array[first] > array[highest]) {
      highest = first;
    }
  }
  return highest;
}

/**
 * Returns the index of the maximum element in 
 * an arraylist of doubles
 *
 * Example use:
 * @code
 * index_t index;
 * ArrayList<double> array;
 * ...
 * index = max_element_index(array);
 * @endcode
 */
int max_element_index(ArrayList<double>& array) {

  int last = array.size() - 1;
  int first = 0;
  int highest = 0;

  if (first == last) {
    return last;
  }
  while (++first <= last) {
    if(array[first] > array[highest]) {
      highest = first;
    }
  }
  return highest;
}