Commands

 Coding Problem Keys 

 Commands 

 Problem Statement 

Series of N commands are passed as input. If the commands is 1, the next input given is added to the queue. If the command is -1, an element is removed from the queue and printed. Fill in the missing lines of code to implement the functions add and poll so that the program runs successfully.

 Boundary Condition(S) 

1 <= N <= 10000

 Input Format 

The first line contains the value of N.

The next N line contains polled integers separated by a space.

 Output Format 

The first line contains polled integers separated by a space.

 Example Input/Output 1 

 Input 

5

1 45

1 67

-1

1 89

-1

 Output 

45 67

 Example Input/Output 2 

 Input 

7

1 67

-1

1 87

1 23

1 89

-1

-1

 Output 

67 87 23

 Note: Max Execution Time Limit: 5000 millisecs 

 Solution 

 Programming Language: C Language 

#include <stdio.h>

struct Node
{
    int data;
    struct Node *next;
};

struct Node *head = NULL;
struct Node *tail = NULL;

void add(int n){
    struct Node *a=(struct Node*)malloc(sizeof(struct Node*));
    a->data=n;
    a->next=NULL;
    if(head==NULL){
        head=a;
        tail=a;
        return;
    }
    tail->next=a;
    tail=a;
    return;
}

int poll(){
    int n=head->data;
    head=head->next;
    return n;
}

// Published By PKJCODERS

int main() {
    int N, value, operation;
    scanf("%d",&N);
    while(N--)
    {
        scanf("%d",&operation);
        if(operation==1)
        {
            scanf("%d",&value);
            add(value);
        }
        else
        {
            printf("%d ",poll());
        }
    }
}

 (Note: Incase If the code doesn't Pass the output kindly comment us with your feedback to help us improvise.)