main2.c

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

typedef struct _Node {
    char val;
    struct _Node *next;
} Node;

Node *head[100005] = {};
Node *tail[100005] = {};
//Node *rev_head[100005] = {};
//Node *rev_tail[100005] = {};

char c[100005] = {};
//int rev[100005] ={};


Node* tmp;
void swap(int a, int b ) {
    //swap(head_node)
    tmp = head[a];
    head[a] = head[b];
    head[b] = tmp;

    // swap(tail_node)
    tmp = tail[a];
    tail[a] = tail[b];
    tail[a]= tmp;

    //swap(rev_head)
//    tmp = rev_head[a];
//    rev_head[a] = rev_head[b];
//    rev_head[b]=tmp;

    //swap(rev_tail)
//    tmp = rev_tail[a];
//    rev_tail[a] = rev_tail[b];
//    rev_tail[b] = tmp;

}

void append(int a, int b) {//pos  ba
    if (head[a] == NULL){
        return;
    }
    if (head[b] == NULL) {
        swap(a, b);
        return;
    }
	if(tail[b])
    tail[b]->next = head[a];
    tail[b] = tail[a];
    head[a] = NULL;
    tail[a] = NULL;

//    rev_tail[a]->next = rev_head[b];
//	rev_head[b] = rev_head[a];
//    rev_head[a] = NULL;
//    rev_tail[a] = NULL;
}

void prepend(int a, int b) {//pre ab
    if (head[a] == NULL){
        return;
    }
    if (head[b] == NULL) {
        swap(a, b);
        return;
    }
	if(tail[a])
    tail[a]->next = head[b];
	head[b] = head[a];
    head[a] = NULL;
    tail[a] = NULL;

//    rev_tail[b]->next = rev_head[a];
//    rev_tail[b] = rev_tail[a];
//    rev_head[a] = NULL;
//    rev_tail[a] = NULL;
}

/*void reverse(int a) {
    //printf("here\n");
    if (head[a] == NULL) return;
//    if(rev[a] == 0 ) rev[a] = 1 ;
//    else rev[a] = 0;
//    printf("here\n");
//    printf("%c",head[a]->val);
    Node* tmp_head , *tmp_tail ;
    tmp_head = head[a];
    tmp_tail = tail[a];
    head[a] = rev_head[a];
    tail[a] = rev_tail[a];
    rev_head[a] = tmp_head ;
    rev_tail[a] = tmp_tail;
    //printf("%c",head[a]->val);
}*/

int main() {
    int N;
    scanf("%d", &N);
    for (int i = 1; i <= N; i++) {
        int n;
        scanf("%d", &n);
        Node *tmp ;
//        rev_head[i] = malloc(sizeof(Node));
        head[i] = malloc(sizeof(Node));
        //--
        if(n!=0){
            scanf("%s", c);
            head[i]->val = c[0];
            head[i]->next = NULL;
            tmp = head[i];
            for (int j = 1; j < n; j++) {
                tmp->next = malloc(sizeof(Node));
                tmp = tmp->next;
                tmp->val = c[j];
                tmp->next = NULL;
            }
            tail[i] = tmp;

            /*
            rev_head[i]->val = c[n - 1];
            rev_head[i]->next = NULL;
            tmp = rev_head[i];
            for (int j = n-2 ; j >= 0; j--) {
                tmp->next = malloc(sizeof(Node));
                tmp = tmp->next;
                tmp->val = c[j];
                tmp->next = NULL;
            }
            rev_tail[i] = tmp;
            */
        }else{
            head[i]=NULL;
//            rev_head[i]=NULL;
            tail[i]=NULL;
//            rev_tail[i]=NULL;
        }
    }

    int q;
    scanf("%d", &q);

    for (int i = 0; i < q; i++) {
        int type, a, b;
        scanf("%d",&type);
        if(type == 4) {
            scanf("%d",&a);
        }
        else{
            scanf("%d%d",  &a, &b);
        }
        if (type == 1) {
            prepend(a, b);
        } else if (type == 2) {
            append(a, b);
        } else if (type == 3) {
            swap(a, b);
        } else {
//            reverse(a);
        }
        
		for(int j=1; j<=N ; j++){
            Node* output;
            output = head[j] ;
            printf("%d:",j);
            while(output!=NULL){
                printf("%c",output->val);
                output = output->next;
            }
            printf("\n");
        }
		puts("");
		
    }
    for(int i=1 ; i<=N ; i++){
		Node* output;
//		if(!rev[i]) {
			output = head[i] ;
			while(output!=NULL){
				printf("%c",output->val);
				output = output->next;
			}
			printf("\n");
		/*} else {
			output = rev_head[i];
			while(output!=NULL){
				printf("%c",output->val);
				output = output->next;
			}
			printf("\n");
		}*/
    }

	for(int i=1;i<=N;i++) {
        Node *tmp;
        tmp = head[i];
        while (tmp) {
            Node *_ = tmp;
            tmp = tmp->next;
            free(_);
        }
//	tmp = rev_head[i];
//		while(tmp) {
//			Node* _ = tmp;
//			tmp = tmp->next;
//			free(_);
//		}
    }
}