Thread: Sorting alphabetically in C using strcmp

Hi, everybody!


I'm working linked list. But It doesn't work! Why? Please help me.

Code:

.....
.....
cityNode *insertNewRecord(cityNode *listNode, int id, char name[], int Counter){ 

    int i,j;

    //char temp[MAX_SIZE];

    cityNode *newRecord = (cityNode*)malloc(sizeof(cityNode));

    cityNode *temp;

 

        newRecord->id = id;

        strcpy(newRecord->name,name);

        newRecord->next = listNode;

        listNode = newRecord;

 

    if(Counter!=1){

 

        for(i = 0; i < Counter-1; i++){

            for(j = 0; j < Counter-i-1;j++){

                if(strcmp(newRecord[j+1].name,newRecord[j].name) <= 0){

                  temp = newRecord->name[j];

                  newRecord->name[j] = newRecord->name[j+1];

                  newRecord->name[j+1] = temp;

                }

            }

        }

    }

 

    return listNode; 

}
...
...

Hi Salem thank you your helping.

It is right code??

Code:

cityNode *insertNewRecord(cityNode *listNode, int id, char name[], int Counter){

    int i,j,TEM;
    char temp[MAX_SIZE];
    cityNode *newRecord = (cityNode*)malloc(sizeof(cityNode));
//    cityNode *temp;


        newRecord->id = id;
        strcpy(newRecord->name,name);
        newRecord->next = listNode;
        listNode = newRecord;


    if(Counter!=1){


        for(i = 0; i < Counter-1; i++){
            for(j = 0; j < Counter-i-1;j++){
                if(strcmp(newRecord[j+1].name,newRecord[j].name) < 0){
                    strcpy(temp,newRecord[j+1].name);
                    TEM = newRecord[j+1].id;
                    strcpy(newRecord[j+1].name,newRecord[j].name);
                    newRecord[j+1].id = newRecord[j].id;
                    strcpy(newRecord[j].name,temp);
                    newRecord[j].id = TEM;
                    }
                }
        }


    }


    return listNode;
}

Salem, It doesn't work.

Code:

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


#define MAX_SIZE 30


typedef struct Cities{
    char name[20];
    int id;
    struct Cities *next;
}cityNode;


cityNode *deleteRecord(cityNode *listNode,int pCode);
void traverseTheList(cityNode *Node);
cityNode *insertNewRecord(cityNode *listNode, int id, char name[], int Counter);
char getOption();
void printMenu();
int main()
{
   int id, Counter = 0, pCode;
   char name[MAX_SIZE], option;
   cityNode *linkList = NULL;


   static const char exitValue = '4';


   printMenu();


   do{
    switch(option = getOption()){
    case '1':
        Counter++;
        printf("\n");
        printf("Sehir plakasi: ");
        scanf("%d",&id);
        fflush(stdin);
        printf("Sehir ismi: ");
        gets(name);
        fflush(stdin);
        linkList = insertNewRecord(linkList,id,name,Counter);
        break;
    case '2':
        Counter--;
        printf("\nPlaka Kodu: ");
        scanf("%d",&pCode);
        linkList = deleteRecord(linkList,pCode);
        break;
    case '3':
        traverseTheList(linkList);
        break;


    }


   }while(exitValue !=  option);




    return 0;
}


void traverseTheList(cityNode *Node){


    cityNode *list = Node;


    while(list!=NULL){
        printf("\n");
        printf("%d --> %s",list->id,list->name);
        list = list->next;
    }


    printf("\n");
}


cityNode *deleteRecord(cityNode *listNode,int pCode){


    cityNode *previousNode;
    cityNode *node = listNode;


    if(listNode == NULL){
        printf("\nListe bos.\n");
        return NULL;
    }


    if(node->id == pCode){
        printf("\nKayit Silindi.\n");
        node = listNode;
        free(node);
        listNode = listNode->next;
        return listNode;
    }
    else{
        while(node != NULL && node->id != pCode){
            previousNode = node;
            node = node->next;
        }
        if(node == NULL){
            printf("Kayit bulunamadi.");
            return NULL;
        }
        else if(node->id == pCode){
            printf("\nKayit Silindi.\n");
            previousNode->next = node->next;
            free(node);
            return listNode;
        }
    }
}


cityNode *insertNewRecord(cityNode *listNode, int id, char name[], int Counter){


    int i,j,TEM;
    char temp[MAX_SIZE];
    cityNode *newRecord = (cityNode*)malloc(sizeof(cityNode));
//    cityNode *temp;


        newRecord->id = id;
        strcpy(newRecord->name,name);
        newRecord->next = listNode;
        listNode = newRecord;


    if(Counter!=1){


        for(i = 0; i < Counter-1; i++){
            for(j = 0; j < Counter-i-1;j++){
                if(strcmp(newRecord[j+1].name,newRecord[j].name) < 0){
                    strcpy(temp,newRecord[j+1].name);
                    TEM = newRecord[j+1].id;
                    strcpy(newRecord[j+1].name,newRecord[j].name);
                    newRecord[j+1].id = newRecord[j].id;
                    strcpy(newRecord[j].name,temp);
                    newRecord[j].id = TEM;
                    }
                }
        }


    }


    return listNode;
}
char getOption(){


    char opt;
    printf("Secenek: ");


    switch(opt = getch()){
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':return opt;
        default:printf("Gecersiz bir islem yapildi\n");
    }


    return opt;
}


void printMenu(){
    printf("----------------------------------\n");
    printf("1 - Yeni kayit ekle\n");
    printf("2 - Kayit sil\n");
    printf("3 - Listeyi goster\n");
    printf("4 - Cikis\n");
    printf("----------------------------------\n");
}

"It doesn't work" does not tell us a whole lot. What input are you giving it, what output are you expecting, and what output are you actually getting?

Also, it would be a lot easier for us to run/test your code if the prompts were in english.

---

Some other things...

Check your compiler warnings:

Code:

/*
main.c|170|warning: implicit declaration of function 'getch'|
main.c||In function 'deleteRecord':|
main.c|123|warning: control reaches end of non-void function|
||=== Build finished: 0 errors, 2 warnings ===|
*/

"getch()" is non-standard, and not a part of any of the headers you included. Use "getchar()" instead.

Your "deleteRecord()" function might not always return a value, based on how your logic is structured. Since you're assigning this return value to a variable elsewhere, your code has the potential for undefined behavior, if control reaches the end of that function without seeing a "return".

• Don't use "gets()": FAQ > Why gets() is bad / Buffer Overflows - Cprogramming.com
• An alternative is described here: FAQ > Get a line of text from the user/keyboard (C) - Cprogramming.com
• Don't fflush the input: FAQ > Why fflush(stdin) is wrong - Cprogramming.com
• Don't cast the return value of "malloc()": FAQ > Casting malloc - Cprogramming.com
• You should check the return value of "malloc()" to make sure it succeeded
• Identifiers in ALL CAPS are typically reserved for constants/macros
• A function should do one thing and do it well. A function called "insertNewRecord()" should only insert a new record. A separate function should be created for sorting.