﻿ C++ - Count number of nodes in a linked list

# C++ Linked List Exercises: Count number of nodes in a linked list

## C++ Linked List: Exercise-3 with Solution

Write a C++ program to create a singly linked list of n nodes and count the number of nodes.

Visualization:

Test Data:
13 11 9 7 5 3 1
Number of nodes in the said Linked list:
7

Sample Solution:

C++ Code:

``````#include <iostream>

using namespace std;

//Declare node
struct Node{
int num;
Node *next;
};

//Insert node at start
void insert_Node(int n){
struct Node *new_node=new Node;
new_node->num=n;
}
int count_Nodes() {

//Create a temporary node(tmp) pointing to the head.

// Count the nodes by creating a variable.
int ctr = 0;

// In the event that the temp node is not null,
// increase ctr by 1 and move on to the next node.
// The process should be repeated until the temp is null.
while(tmp != NULL) {
ctr++;
tmp = tmp->next;
}

//return ctr
return ctr;
}
//Display all nodes
void display_all_nodes()
{
while(temp!=NULL){
cout<<temp->num<<" ";
temp=temp->next;
}
}

int main(){
insert_Node(1);
insert_Node(3);
insert_Node(5);
insert_Node(7);
insert_Node(9);
insert_Node(11);
insert_Node(13);
display_all_nodes();
cout<<"\nNumber of nodes in the said Linked list:\n";
int ctr = count_Nodes();
cout << ctr;
cout<<endl;
return 0;
}
``````

Sample Output:

```Original Linked list:
13 11 9 7 5 3 1
Number of nodes in the said Linked list:
7
```

Flowchart:

CPP Code Editor:

Previous C++ Exercise: Reverse linked list.
Next C++ Exercise: Insert a new node at the beginning of a Linked List.

What is the difficulty level of this exercise?

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## C++ Programming: Tips of the Day

How to replace all occurrences of a character in string?

std::string doesn't contain such function but you could use stand-alone replace function from algorithm header.

```#include <algorithm>
#include <string>

void some_func() {
std::string s = "example string";
std::replace( s.begin(), s.end(), 'x', 'y'); // replace all 'x' to 'y'
}
```

Ref: https://bit.ly/3niU71x