house_robber.cpp File Reference

Implementation of House Robber Problem algorithm. More...

#include <cassert>
#include <climits>
#include <iostream>
#include <vector>

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Namespaces
namespace	dynamic_programming
	Dynamic Programming algorithms.
namespace	house_robber
	Functions for the House Robber algorithm.

Functions
std::uint32_t	dynamic_programming::house_robber::houseRobber (const std::vector< uint32_t > &money, const uint32_t &n)
	The main function that implements the House Robber algorithm using dynamic programming. More...
static void	test ()
	Self-test implementations. More...
int	main ()
	Main function. More...

Detailed Description

Implementation of House Robber Problem algorithm.

Solution of House robber problem uses a dynamic programming concept that works in \(O(n)\) time and works in \(O(1)\) space.

Author

Swastika Gupta

Function Documentation

houseRobber()

std::uint32_t dynamic_programming::house_robber::houseRobber	(	const std::vector< uint32_t > &	money,
		const uint32_t &	n
	)

The main function that implements the House Robber algorithm using dynamic programming.

Parameters

money	array containing money in the ith house
n	size of array

Returns

maximum amount of money that can be robbed

                                             {
    if (n == 0) {  // if there is no house
        return 0;
    }
    if (n == 1) {  // if there is only one house
        return money[0];
    }
    if (n == 2) {  // if there are two houses, one with the maximum amount of
                   // money will be robbed
        return std::max(money[0], money[1]);
    }
    uint32_t max_value = 0;  // contains maximum stolen value at the end
    uint32_t value1 = money[0];
    uint32_t value2 = std::max(money[0], money[1]);
    for (uint32_t i = 2; i < n; i++) {
        max_value = std::max(money[i] + value1, value2);
        value1 = value2;
        value2 = max_value;
    }
 
    return max_value;
}

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main()

int main

(

void

)

Main function.

Returns

0 on exit

           {
    test();  // run self-test implementations
    return 0;
}

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test()

static void test ( )

static

Self-test implementations.

Returns

void

                   {
    // Test 1
    // [1, 2, 3, 1] return 4
    std::vector<uint32_t> array1 = {1, 2, 3, 1};
    std::cout << "Test 1... ";
    assert(
        dynamic_programming::house_robber::houseRobber(array1, array1.size()) ==
        4);  // here the two non-adjacent houses that are robbed are first and
             // third with total sum money as 4
    std::cout << "passed" << std::endl;
 
    // Test 2
    // [6, 7, 1, 3, 8, 2, 4] return 19
    std::vector<uint32_t> array2 = {6, 7, 1, 3, 8, 2, 4};
    std::cout << "Test 2... ";
    assert(
        dynamic_programming::house_robber::houseRobber(array2, array2.size()) ==
        19);  // here the four non-adjacent houses that are robbed are first,
              // third, fifth and seventh with total sum money as 19
    std::cout << "passed" << std::endl;
 
    // Test 3
    // [] return 0
    std::vector<uint32_t> array3 = {};
    std::cout << "Test 3... ";
    assert(
        dynamic_programming::house_robber::houseRobber(array3, array3.size()) ==
        0);  // since there is no house no money can be robbed
    std::cout << "passed" << std::endl;
 
    // Test 4
    // [2,7,9,3,1] return 12
    std::vector<uint32_t> array4 = {2, 7, 9, 3, 1};
    std::cout << "Test 4... ";
    assert(
        dynamic_programming::house_robber::houseRobber(array4, array4.size()) ==
        12);  // here the three non-adjacent houses that are robbed are first,
              // third and fifth with total sum money as 12
    std::cout << "passed" << std::endl;
}

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