Write a function insert$()$ to insert a node to a linked list. A linked list contains a series of nodes and each node holds a value and the values. Each node contains a pointer used to link to the next node. The values in the linked list are in a sorted order. The function insert$()$ will insert a node into the linked list in sorted fashion. A linked list starts with a pointer to the first node. If the pointer points to NULL, then it is an empty list. Complete the following program by implementing the insert$()$friend function. The output of the program is

$01234$

class Node

$\{$

public:

$$ Node$()$;

$$ Node$($int val$)$;

$$ int getValue$()$;

$$ Node $*$getLink$()$;

$$ void setLink$($Node &nd$)$;

$$ friend void insert$($Node$*$ &head, Node $*$nd$)$;

$$ friend ostream& operator $<<($ostream &ost, Node $*$head$)$;

private:

$$ int value;

$$ Node $*$link;

$\}$;

Node::Node$()$ : value$(0),$ link$($NULL$)$

$\{\}$

Node::Node$($int val$)$ : value$($val$),$ link$($NULL$)$

$\{\}$

Node$*$ Node::getLink$()$

$\{$

$$ return this$->$link;

$\}$

int Node::getValue$()$

$\{$

$$ return this$->$value;

$\}$

void Node::setLink$($Node &nd$)$

$\{$

$$ this$->$link $=$ &nd;

$\}$

void insert$($Node$*$ &head, Node $*$nd$)$

$\{$

$/*$ Implement insert$()$ function $*/$

$\}$

ostream & operator $<<($ostream &ost, Node $*$head$)$

$\{$

$$ Node $*$cur $=$ head;

$$ while $($cur $!=$ NULL$)$

$\{$

$$ ost $<<$ cur$->$value;

$$ cur $=$ cur$->$link;

$\}$

$$ return ost;

$\}$

int main$()\{$

$$ int data$[5]=\{3,1,2,0,4\}$;

$$ Node $*$nd;

$$ Node $*$head $=$ NULL;

$$ for $($int i $=0$; i $<5$; i$++)$

$\{$

$$ nd $=$ new Node$($data$[$i$])$;

$$ insert$($head$,$ nd$)$;

$\}$

$$ cout $<<$ head $<<$ endl;

$$ return $0$;

$\}$