/*
  this file contains a number of sample functions and other techniques 
concerning arrays, loops, and strings
*/

#include<iostream.h>
#include<string>

// Function to print contents of integer array, with elements separated by
// spaces and a carriage return at the very end:
void printarray(int A[], int size)
{ int i;  // loop counter, to go through array
  for(i=0;i<size;i++)
    {    cout <<  A[i] << " "; }
  cout << endl;
}

// Function to return the sum of all elements in an array of doubles:
double sum(double A[], int size)
{  double accumulator;  // keeps track of running sum.
   int i;    // loop counter to go through array indices
   accumulator = 0.0;
   i = 0;
   while (i<size)
    {
      accumulator = accumulator + A[i];
      i++;
    } // end while   
// for loop equilvaent: for(i=0;i<size;i++) accumulator += A[i];

   return A[i];  // question: why not return A[i] INSIDE LOOP?
}  // sum



// function to return the largest element in an array of integers:
int max(int A[], int length)
{ int i;  // loop counter
  int candidate;  // largest seen so far;
  candidate = A[0];
  i = 1;   // 0th element already taken into account
  while (i < length)
    {
      if (candidate < A[i])  // larger value found
	{ candidate = A[i]; }  
      i++;
    }
  return candidate;
}  // max

//function to return the INDEX of the largest element in an array of integers:
int Indexmax(int A[], int length)
{ int i;  // loop counter
  int candidate;  // largest seen so far;
  int candidateIndex; // index of largest seen so far
  candidate = A[0];
  candidateIndex = 0;
  i = 1;   // 0th element already taken into account
  while (i < length)
    {
      if (candidate < A[i])  // larger value found
	{ candidate = A[i]; 
	  candidateIndex = i;
        } // if 
      i++;
    }
  return candidateIndex;
}  // max


// function that returns true if x is inside array A, and false otherwise:
bool inarray(int x, int A[], int size)
{  int i; // loop counter
   bool answer = false;  // initially, haven't found x yet, so answer is false
   i = 0;
   while (i<size && !answer)  // stops as soon as answer becomes true
     {
       if (x == A[i]) answer = true;  // found it!
       i++;
     } // while

   // do not return true from inside a while loop!

   /* for loop form:
      for(i=0; i<size && !answer; i++)
      {  if (x == A[i]) answer = true;  }
   */
   return answer;
 } // inarray




// function that contructs the reverse of string a
// Note: the size is not a separate parameter because it's encapsulated
// within the string object a:
string reverse(string a)
{ int i;  // loop counter
  string b;  // new string to be constructed
  b = "";  // will add to b char by char
  i = 0;
  while (i<a.size())
    {
      b = a[i] + b;  // adds a char to the front of b
      i++;
    } // while
  return b;
} // reverse

// function that returns true if string a consists of only capital letters:
bool capitals(string a)
{ int i;
  bool answer;
  int asciival;  // temp var to hold ascii value of a char
  answer = true; // algorithm is to assume true, and see if it's false
  i = 0;
  while (i<a.size() && answer==true)
    {
      asciival = (int) a[i];  // convert char to its ascii code
      if (asciival < 65 || asciival > 90)
         answer = false;  // non-upper case char found!
      i++;
    }  // end while
    return answer;
} // capitals

int main()
{
  int A[5] = {1,7,9,5,3};
  double B[3] = {1.2,3.4,5.6};
  string S;
  S = "hello";

  printarray(A,5);
  cout << sum(B,5) << " " << max(A,5) << " " << Indexmax(A,5) << endl;
  if (inarray(4,A,5)) cout << "4 is in A\n"; 
     else cout << "4 is not in A\n";

  cout << reverse(S) << endl;
  cout << capitals(S) << endl;  // prints 1 for true, 0 for false
  return 0;
}