// piecetest.cxx - does three tests of list_piece implementation
// cmc, 10/23/2015

#include "listpiece.h"
#include <iostream>
#include <cstdlib>
using namespace std;
using namespace main_savitch_5;

void print_list(const node *start_ptr);
    // prints list values from start_ptr to end of list
void print_array(double array[], size_t start, size_t end);
    // prints array elements from start to just before end
void do_test(double data[], const node *datalist, size_t mid);
    // tests and shows results of using list_piece to split at mid

const size_t SIZE = 20; // global constant

int main() {
    double data[SIZE];
    size_t i;
    for (i = 0; i < SIZE; i++) data[i] = i+1;
    
    // make a list of SIZE nodes in order of data and print it
    node *datalist = NULL, *ptr;
    list_head_insert(datalist, data[0]);
    for (i = 1, ptr = datalist; i < SIZE; i++, ptr=ptr->link())
        list_insert(ptr, data[i]);
    cout << "Here is the whole original list:" << endl;
    print_list(datalist);
    
    // test two (about) equal pieces
    cout << "\nTEST 1 - two equal parts." << endl;
    size_t mid = SIZE / 2;
    do_test(data, datalist, mid);
    
    // test for first piece just head
    cout << "\nTEST 2 - first part just first node." << endl;
    do_test(data, datalist, 1);
    
    // test for second piece just tail
    cout << "\nTEST 3 - second part just last node." << endl;
    do_test(data, datalist, SIZE-1);
    
    return 0;
}

void print_list(const node *start_ptr) {
    const node *n = start_ptr;
    while (n) {
        cout << n->data() << " ";
        n = n->link();
    }
    cout << endl;
}

void print_array(double array[], size_t start, size_t end) {
    for (size_t i = start; i < end; i++)
        cout << array[i] << " ";
    cout << endl;
}

void do_test(double data[], const node *datalist, size_t mid) {
    cout << "Correct split for this test: " << endl;
    print_array(data, 0, mid);
    print_array(data, mid, SIZE);
    
    const node *datamid = list_locate(datalist, mid+1);
    node *copyhead1, *copyhead2, *copytail1, *copytail2;
    
    // Here is where your function gets called twice.
    list_piece(datalist, datamid, copyhead1, copytail1);
    list_piece(datamid, NULL, copyhead2, copytail2);
    
    cout << "Now your two parts:" << endl;
    print_list(copyhead1);
    print_list(copyhead2);
    
    cout << "First piece: head at " << copyhead1->data()
    << "; tail at " << copytail1->data() << endl;
    cout << "Second piece: head at " << copyhead2->data()
    << "; tail at " << copytail2->data() << endl;
}