Linked List Input and Output-CodePudding

I want to create a program in C that differentiates between a number or a character and put them into a linked list, then output the list. The issue is that when I input anything into it, it only outputs 10. In the results down below 1 2 3, I need it to separate the char and the nums. Help will be greatly appreciated

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
 
 
// define a union to overlay an integer with a char
union DataType{
    int operand;
    char operate;
};
 
 
// typedef to rename DataType
typedef union DataType Data;
 
 
// create a structure for a node
typedef struct NodeType{
    Data data;
    struct NodeType* next;
}Node;
 
Node* top = NULL;
 
 
 
 
// typedef to rename NodeType
void displayNode();
 
void addNode() {
    Node * newNode = malloc(sizeof(Node));
    char expression[64];
        // get the stuff
    printf("Enter expression: ");
    fgets(expression, 64, stdin);
    //char array , int size, stdin
 
    for (int i = 0; i < strlen(expression); i  ) { //checks individual character
 
        if (isdigit((expression[i]))){  // if digit add it to operate
 
            (*newNode).data.operate = (expression[i]); // how
        }else //else add it to operand
            newNode->data.operand = (expression[i]); //how
    }
    if (top == NULL)
        top = newNode;             // update headPtr in main
    else {
        Node *currPtr = top;
 
        // find last Node
        while (currPtr->next != NULL)
            currPtr = currPtr->next;
 
        // insert new Node
        currPtr->next = newNode;
    }
}
 
void popNode()
{
    if(top != NULL)
    {
        Node * temp = top;
        top = top->next;
        free(temp);
    }
}
 
 
void displayNode()
{
    if(top == NULL)
    {
        printf("Error");
        return;
    }
    Node * curr = top;
//    while(curr -> next != NULL){
        printf("\n --------------------------------- ");
        printf("\nOperator stack: ");
        printf("%c ", curr->data.operate);
 
 
        printf("\nOperand stack: ");
        printf("%d ", curr->data.operand);
        printf("\n --------------------------------- ");
 
        curr = curr->next;
//    }
}
 
 
int main()
{
    int menu = 1;
 
    do {
 
        //call an array in main
 
        addNode(&top);
 
        displayNode(&top);
 
        char cont;
        printf("\nDo you want to enter another expression (Y/N)?");
 
        scanf(" %c", &cont);
 
        if (cont == 'n'|| cont == 'N') { // if not close menu
            menu = 0;
        }
 
    }while(menu == 1);
    return 0;
}

Enter expression:1 2 3

 --------------------------------- 
Operator stack:

Operand stack: 10
 --------------------------------- 
Do you want to enter another expression (Y/N)?

CodePudding user response：

Testing out your code quickly indicated that the addNode function was only creating one initial node. That is why you only see one operator stack output. With that I moved the node creation line of code along with the node linkage loop inside the for loop.

Following is a revised version of your code with the noted changes in the addNode function.

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>

// define a union to overlay an integer with a char
union DataType
{
    int operand;
    char operate;
};

// typedef to rename DataType
typedef union DataType Data;

// create a structure for a node
typedef struct NodeType
{
    Data data;
    struct NodeType* next;
} Node;

Node* top = NULL;

// typedef to rename NodeType
void displayNode();

void addNode()
{

    char expression[64];
    // get the stuff
    printf("Enter expression: ");
    fgets(expression, 64, stdin);
    //char array , int size, stdin

    for (int i = 0; i < strlen(expression); i  )   //checks individual character
    {
        Node * newNode = malloc(sizeof(Node));      /* Moved this line of code here to build multiple nodes */
        if (isdigit((expression[i])))   // if digit add it to operate
        {
            (*newNode).data.operate = (expression[i]); // how
        }
        else  //else add it to operand
            newNode->data.operand = (expression[i]); //how
        /* Moved this block of code inside the for loop to create the linked list */
        if (top == NULL)
            top = newNode;             // update headPtr in main
        else
        {
            Node *currPtr = top;

            // find last Node
            while (currPtr->next != NULL)
                currPtr = currPtr->next;

            // insert new Node
            currPtr->next = newNode;
        }
    }

}

void popNode()
{
    if(top != NULL)
    {
        Node * temp = top;
        top = top->next;
        free(temp);
    }
}

void displayNode()
{
    if(top == NULL)
    {
        printf("Error");
        return;
    }
    Node * curr = top;
    while(curr -> next != NULL){
        printf("\n --------------------------------- ");
        printf("\nOperator stack: ");
        printf("%c ", curr->data.operate);


        printf("\nOperand stack: ");
        printf("%d ", curr->data.operand);
        printf("\n --------------------------------- ");

    curr = curr->next;
    }
}


int main()
{
    int menu = 1;

    do
    {
        //call an array in main

        addNode();

        displayNode();

        char cont;
        printf("\nDo you want to enter another expression (Y/N)?");

        scanf(" %c", &cont);

        if (cont == 'n'|| cont == 'N')   // if not close menu
        {
            menu = 0;
        }

    }
    while(menu == 1);
    return 0;
}

Following was the output at the terminal utilizing your test expression.

@Dev:~/C_Programs/Console/Diff/bin/Release$ ./Diff 
Enter expression: 1 2 3

 --------------------------------- 
Operator stack: 1 
Operand stack: 49 
 --------------------------------- 
 --------------------------------- 
Operator stack:   
Operand stack: 43 
 --------------------------------- 
 --------------------------------- 
Operator stack: 2 
Operand stack: 50 
 --------------------------------- 
 --------------------------------- 
Operator stack:   
Operand stack: 43 
 --------------------------------- 
 --------------------------------- 
Operator stack: 3 
Operand stack: 51 
 --------------------------------- 
Do you want to enter another expression (Y/N)?

I suspect that there is some more refinement that you would probably do but this gets your code to the point of creating multiple nodes and linking them. Give that a try and see if it meets the spirit of your project.