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I have been working on a program in C99 which is based heavily around structs. I found that I could create linked lists of structs, and thought to give it a try.

The following is a miserable attempt, reworked about 50 times, that is meant to do the following:

1) Create a struct of type BASE in the main method, which contains the head of a linked list (CHAIN).

2) Pass this BASE struct to another function, which will append additional CHAIN elements to the end of the linked list.

3) Print the linked lists elements in main, as proof to myself that the changes are not just in the other method.

#include <stdlib.h>
#include <stdio.h>
typedef struct Base {
    //many things
    struct Chain *head;
} BASE;

typedef struct Chain {
    int x;
    struct Chain *next;
} CHAIN;

void extendChain(BASE *Data, int length);

int main() {
    BASE Data;
    CHAIN *pointer;
    Data.head = 0;
    int length = 10; //userInput(); // gets integer
    extendChain(&Data, length);
    pointer = Data.head;
    while (pointer) {
        printf("%d\n", pointer->x);
        pointer = pointer->next;
    }
}

void extendChain(BASE *Data, int length) {
    CHAIN *position;
    position = Data->head;
    for (int i=0; i<length; ++i) {
        if (!Data->head) {
            // this will set the first value, the first time this is run.
            Data->head = malloc(sizeof(CHAIN));
            Data->head->x = -1; // set values here. Irrelevant.
            position = Data->head;
        } else if (position) {
            while (position->next) {
                position = position->next;
            }
            position = malloc(sizeof(CHAIN));
            position->next = 0;
            position->x = i; // placeholder
        }
    }
}

This has turned out terribly, and I realize that my example doesn't begin to work even in theory (but I gave it my best shot). I'm beginning to think that the only way to do this is if I do it all in the same method, which I successfully managed to do earlier, however this will quickly become messy, and a method would definitely be best.

Does anyone have a creative way of adding X elements to a linked list when passed only a struct containing the header of this linked list? Much appreciated, as always.

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2 回答 2

1

代码中的逻辑错误。此代码有效：

void extendChain(BASE *Data, int length) {
    CHAIN *position;
    position = Data->head;
    int i;·
    for (i=0; i<length; ++i) {
        if (!Data->head) {
            // this will set the first value, the first time this is run.
            Data->head = malloc(sizeof(CHAIN));
            Data->head->x = -1; // set values here. Irrelevant.
            Data->head->next = NULL; // <========= 
            position = Data->head; 
        } else if (position) {
            while (position->next) {
                position = position->next;
            }
            CHAIN * position_new_node = malloc(sizeof(CHAIN)); // <========= 
            position_new_node->next = 0; // <========= 
            position_new_node->x = i; // placeholder // <========= 
            position->next = position_new_node; // <========= 
        }
    }
}
于 2013-09-18T12:58:50.433 回答
0

算法

创建原始链表 将要添加的链表发送到函数 Traverse 直到第一个链表的末尾（设指针为 t） 重复： t 旁边的节点=新链表的下一个节点 将两个节点向前移动一个单位直到新链表的下一个节点为 Null

于 2013-09-18T12:52:39.517 回答