//// Exercise - arrays -- SORT entire (shrinking) array 

int a[];
int total;
int biggest;
float y;

void setup() {
  // setup //
  size(600,600);
  a= new int[20];
  reset();
}

void draw() {
  // next frame //
  background(255);
  fill(0);
  textSize( 16 );
  text( "The array size is: "+a.length, 20, 20 );
  text( "Press 'r' key for random values in array.", width/2,20 );
  text( "Press 'b' to move biggest to end", width/2,40 );
  text( "Press 's' to sort entire array.", width/2,60 );

  y= 70;

  for (int j=0; j<a.length; j++) {
    total += a[j];
  }
  showAll( a, a.length);
}

void showAll( int a[], int many ) {  
  for (int j=0; j<many; j++) {
    text( a[j], 50, y);
    y += 20;
  }
  
}

void keyPressed() {
  // keys //
  if (key == 'r') {
    reset();
  }//if//
  if (key == 'b') { bigToEnd( a, a.length ); }
  if (key == 's') { sortAll( a, a.length ); }
}
void reset() {
  //// Fill array with random #s.
      for (int j=0; j<a.length; j++) {
        a[j] = int( random(1000));
      }//for//
}  

/*
void big() {
  //// Find biggest # 
  biggest= a[0];

      for (int j=0; j<a.length; j++) {
        if (a[j] > biggest) biggest=  a[j];
       }
}
*/



int whereBig( int a[], int m ) {
  //// Find INDEX OF biggest # in array a[m]
  int w=0;
      for (int j=0; j<m; j++) {
        if (a[j] > a[w]) w=j;
       }
  return w;
}
void swap( int[] a, int j, int k) {
  // swap two elements of array 
  int tmp; 
  tmp=  a[j];
  a[j]= a[k];
  a[k]=  tmp;
}


void bigToEnd( int a[], int m ) {
  // Move biggest to end
  int w;

  w=  whereBig( a, m );
  swap( a, w, m-1);
}

void sortAll( int a[], int many ) {
  //  Sort the entire array.
  for ( int m=many; m>1; m=m-1 ) {
    bigToEnd( a, m );
  }
}