ivycheung1208

/* CC150 17.13 */
// convert a binary search tree (implemented with BiNode) into a doubly linked list
// the values should be kept in order and the operation should be performed in place

#include <iostream>

using namespace std;

struct BiNode {
	BiNode() : data(0), node1(nullptr), node2(nullptr) {}

ivycheung1208

/* CC150 17.12 */
// find all pairs of integers within an array which sum to a specified value

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

vector<pair<int, int>> findPairs(vector<int> arr, int sum)

ivycheung1208

/* CC150 17.11 */
// implement a method rand7() given rand5()

#include <iostream>
#include <cstdlib>
#include <map>
#define N 10000

using namespace std;

ivycheung1208

/* CC150 17.9 */
// find the frequency of occurrences of any given word in a book

#include <iostream>
#include <string>
#include <unordered_map>
#include <fstream>

using namespace std;

ivycheung1208

/* CC150 17.8 */
// find the contiguous sequence with the largest sum, return the sum
// book solution

#include <iostream>
#include <vector>

using namespace std;

// what if required to return start and end indices of the sequence?!!

ivycheung1208

/* CC150 17.7 */
// print an English phrase that describes the given integer
// http://en.wikipedia.org/wiki/English_numerals

#include <iostream>
#include <string>

using namespace std;

string digits[] = { "Zero",  "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine" };

ivycheung1208

/* CC150 17.6 */
// find the smallest sequence m through n s.t. by sorting this sequence the entire array would be sorted

#include <iostream>
#include <vector>

using namespace std;

pair<int, int> findSeq(vector<int> arr)
{

ivycheung1208

/* CC150 17.5 */
// the game of master mind (RGBY)

#include <iostream>
#define N 4

class Result {
public:
	Result() : hits(0), phits(0) {}
	Result(int h, int p) : hits(h), phits(p) {}

ivycheung1208

/* CC150 17.4 */
// find the maximum of two numbers without if-else or any comparison operator

#include <iostream>

int sign(int n) { return (n >> 31) & 0x1 ^ 1; } // 1 for positive and 0 for negative

int maxNumber(int a, int b)
{
	// if ab < 0, return the positive one, filt = sign(a)

ivycheung1208

/* CC150 17.3 */
// compute the number of tailing zeros in n factorial

#include <iostream>

int tailZeros(int n)
{
	int count = 0;
	for (int fact = 5; fact <= n; fact += 5) {
		for (int j = fact; j % 5 == 0; j /= 5)