struct node {
    char *string;
    struct node *next;
};

struct node *sw1, *sw2, *sw1_head;

//first 1 and first2 is the head of linked lists that holds text's each word seperatly. i created before.

first1 = first1_head; // _ head is the same as first1 and first2
first2 = first2_head;

//sw1 and sw2 are the pointers that holds always second words.
sw2 = first2->next;
sw1 = first1->next;
sw1_head = sw1;

//these chars are used to concat two words
char destination1[50];
char destination2[50];

while(sw2 != NULL){

        strcpy(destination2,first2->string);
        strcat(destination2,sw2->string);

        while(sw1 != NULL){

        strcpy(destination1,first1->string);
        strcat(destination1,sw1->string);
    //  printf("%sn", destination1);
        if(strcmp(destination2, destination1) == 0) {

            insert(&matched2, destination1);//matched holds common words

            }

            sw1 = sw1->next;
            first1 = first1->next;

        }

        sw1 = sw1_head;//sets both sw1 and first1 to their past positions.
        first1 = first1_head;
        sw2 = sw2->next;
        first2 = first2->next;
    }