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;
}