TheAlgorithms-C-Plus-Plus/dynamic_programming/0-1 Knapsack.cpp

//0-1 Knapsack problem - Dynamic programming
//#include <bits/stdc++.h>
#include <iostream>
using namespace std;

//void Print(int res[20][20], int i, int j, int capacity)
//{
//	if(i==0 || j==0)
//	{
//		return;
//	}
//	if(res[i-1][j]==res[i][j-1])
//	{
//		if(i<=capacity)
//		{
//			cout<<i<<" ";
//		}
//
//		Print(res, i-1, j-1, capacity-i);
//	}
//	else if(res[i-1][j]>res[i][j-1])
//	{
//		Print(res, i-1,j, capacity);
//	}
//	else if(res[i][j-1]>res[i-1][j])
//	{
//		Print(res, i,j-1, capacity);
//	}
//}

int Knapsack(int capacity, int n, int weight[], int value[])
{
	int res[20][20];
	for (int i = 0; i < n + 1; ++i)
	{
		for (int j = 0; j < capacity + 1; ++j)
		{
			if (i == 0 || j == 0)
				res[i][j] = 0;
			else if (weight[i - 1] <= j)
				res[i][j] = max(value[i - 1] + res[i - 1][j - weight[i - 1]], res[i - 1][j]);
			else
				res[i][j] = res[i - 1][j];
		}
	}
	//	Print(res, n, capacity, capacity);
	//	cout<<"\n";
	return res[n][capacity];
}
int main()
{
	int n;
	cout << "Enter number of items: ";
	cin >> n;
	int weight[n], value[n];
	cout << "Enter weights: ";
	for (int i = 0; i < n; ++i)
	{
		cin >> weight[i];
	}
	cout << "Enter values: ";
	for (int i = 0; i < n; ++i)
	{
		cin >> value[i];
	}
	int capacity;
	cout << "Enter capacity: ";
	cin >> capacity;
	cout << Knapsack(capacity, n, weight, value);
	return 0;
}