toys/data-structures/largestProduct/largestProduct.cpp

#include <iostream>
#include <string>
using namespace std;

// Structures
struct stack {
	int items[1000];
	int stackTop;
};

// Prototypes
void push (stack &, int);
int  pop (stack &);
bool isEmpty (stack &);
void initStack (stack &);

// --------------------------------
// main
// --------------------------------
int main() {
	
	// Variables, the stack, and the array
	int num1 = 0, num2 = 0, num3 = 0, num4 = 0, num5 = 0;
	int temp = 0, max = 0, counter = 0;
	stack myStack;
	initStack(myStack);
	int array[1000] = {
		7,3,1,6,7,1,7,6,5,3,1,3,3,0,6,2,4,9,1,9,2,2,5,1,1,
		9,6,7,4,4,2,6,5,7,4,7,4,2,3,5,5,3,4,9,1,9,4,9,3,4,
		9,6,9,8,3,5,2,0,3,1,2,7,7,4,5,0,6,3,2,6,2,3,9,5,7,
		8,3,1,8,0,1,6,9,8,4,8,0,1,8,6,9,4,7,8,8,5,1,8,4,3,
		8,5,8,6,1,5,6,0,7,8,9,1,1,2,9,4,9,4,9,5,4,5,9,5,0,
		1,7,3,7,9,5,8,3,3,1,9,5,2,8,5,3,2,0,8,8,0,5,5,1,1,
		1,2,5,4,0,6,9,8,7,4,7,1,5,8,5,2,3,8,6,3,0,5,0,7,1,
		5,6,9,3,2,9,0,9,6,3,2,9,5,2,2,7,4,4,3,0,4,3,5,5,7,
		6,6,8,9,6,6,4,8,9,5,0,4,4,5,2,4,4,5,2,3,1,6,1,7,3,
		1,8,5,6,4,0,3,0,9,8,7,1,1,1,2,1,7,2,2,3,8,3,1,1,3,
		6,2,2,2,9,8,9,3,4,2,3,3,8,0,3,0,8,1,3,5,3,3,6,2,7,
		6,6,1,4,2,8,2,8,0,6,4,4,4,4,8,6,6,4,5,2,3,8,7,4,9,
		3,0,3,5,8,9,0,7,2,9,6,2,9,0,4,9,1,5,6,0,4,4,0,7,7,
		2,3,9,0,7,1,3,8,1,0,5,1,5,8,5,9,3,0,7,9,6,0,8,6,6,
		7,0,1,7,2,4,2,7,1,2,1,8,8,3,9,9,8,7,9,7,9,0,8,7,9,
		2,2,7,4,9,2,1,9,0,1,6,9,9,7,2,0,8,8,8,0,9,3,7,7,6,
		6,5,7,2,7,3,3,3,0,0,1,0,5,3,3,6,7,8,8,1,2,2,0,2,3,
		5,4,2,1,8,0,9,7,5,1,2,5,4,5,4,0,5,9,4,7,5,2,2,4,3,
		5,2,5,8,4,9,0,7,7,1,1,6,7,0,5,5,6,0,1,3,6,0,4,8,3,
		9,5,8,6,4,4,6,7,0,6,3,2,4,4,1,5,7,2,2,1,5,5,3,9,7,
		5,3,6,9,7,8,1,7,9,7,7,8,4,6,1,7,4,0,6,4,9,5,5,1,4,
		9,2,9,0,8,6,2,5,6,9,3,2,1,9,7,8,4,6,8,6,2,2,4,8,2,
		8,3,9,7,2,2,4,1,3,7,5,6,5,7,0,5,6,0,5,7,4,9,0,2,6,
		1,4,0,7,9,7,2,9,6,8,6,5,2,4,1,4,5,3,5,1,0,0,4,7,4,
		8,2,1,6,6,3,7,0,4,8,4,4,0,3,1,9,9,8,9,0,0,0,8,8,9,
		5,2,4,3,4,5,0,6,5,8,5,4,1,2,2,7,5,8,8,6,6,6,8,8,1,
		1,6,4,2,7,1,7,1,4,7,9,9,2,4,4,4,2,9,2,8,2,3,0,8,6,
		3,4,6,5,6,7,4,8,1,3,9,1,9,1,2,3,1,6,2,8,2,4,5,8,6,
		1,7,8,6,6,4,5,8,3,5,9,1,2,4,5,6,6,5,2,9,4,7,6,5,4,
		5,6,8,2,8,4,8,9,1,2,8,8,3,1,4,2,6,0,7,6,9,0,0,4,2,
		2,4,2,1,9,0,2,2,6,7,1,0,5,5,6,2,6,3,2,1,1,1,1,1,0,
		9,3,7,0,5,4,4,2,1,7,5,0,6,9,4,1,6,5,8,9,6,0,4,0,8,
		0,7,1,9,8,4,0,3,8,5,0,9,6,2,4,5,5,4,4,4,3,6,2,9,8,
		1,2,3,0,9,8,7,8,7,9,9,2,7,2,4,4,2,8,4,9,0,9,1,8,8,
		8,4,5,8,0,1,5,6,1,6,6,0,9,7,9,1,9,1,3,3,8,7,5,4,9,
		9,2,0,0,5,2,4,0,6,3,6,8,9,9,1,2,5,6,0,7,1,7,6,0,6,
		0,5,8,8,6,1,1,6,4,6,7,1,0,9,4,0,5,0,7,7,5,4,1,0,0,
		2,2,5,6,9,8,3,1,5,5,2,0,0,0,5,5,9,3,5,7,2,9,7,2,5,
		7,1,6,3,6,2,6,9,5,6,1,8,8,2,6,7,0,4,2,8,2,5,2,4,8,
		3,6,0,0,8,2,3,2,5,7,5,3,0,4,2,0,7,5,2,9,6,3,4,5,0
	};
	
	// Introduce the program
	cout << "------------------------------------------------" << endl;
	cout << "   Finding the product of consecutive numbers   " << endl;
	cout << "------------------------------------------------" << endl;
	cout << endl;
	cout << "This program takes a 1,000-digit integer, stored" << endl;
	cout << "as an array, and finds the largest product of" << endl;
	cout << "five consecutive numbers in the integer." << endl;
	cout << endl;
	cout << "Processing..." << endl;
	cout << endl;
	
	// Get the array onto the stack
	for (counter = 0; counter < 1000; ++counter)
		push(myStack, array[counter]);
	
	// Do work
	while (!isEmpty(myStack)) {
		num1 = pop(myStack);
		num2 = pop(myStack);
		num3 = pop(myStack);
		num4 = pop(myStack);
		num5 = pop(myStack);
		
		temp = num1 * num2 * num3 * num4 * num5;
		
		if (temp > max) {
			max = temp;
		}
		
		if (!isEmpty(myStack)) {
			push(myStack, num5);
			push(myStack, num4);
			push(myStack, num3);
			push(myStack, num2);
		}
	}
	
	cout << "The largest product is " << max << endl;
	
	cout << endl;
	cout << "------------------------------------------------" << endl;
	cout << "\\\\//_ Live long and prosper." << endl;
	
	return (0);
} // End main

// --------------------------------
// push
// --------------------------------
void push (stack & myStack, int n) {
	myStack.items[++myStack.stackTop] = n;
} // End push

// --------------------------------
// pop
// --------------------------------
int pop (stack & myStack) {
	int result;
	
	result = myStack.items[myStack.stackTop--];
	return result;
} // End pop

// --------------------------------
// isEmpty
// --------------------------------
bool isEmpty (stack & myStack) {
	return (myStack.stackTop < 0);
} // End isEmpty

// --------------------------------
// initStack
// --------------------------------
void initStack (stack & myStack) {
	myStack.stackTop = -1;
} // End initStack