题解 | #从单向链表中删除指定值的节点#

按照题意，使用单链表来解决这道问题。

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

typedef struct Linkedlist {
    int val;
    struct Linkedlist* next;
} Linkedlist;

/* 创建节点*/
Linkedlist* LLCreateNode(int val) {
    Linkedlist* node = (Linkedlist*)malloc(sizeof(Linkedlist));
    if (node == NULL) {
        return NULL;
    }
    node->val = val;
    node->next = NULL;
    return node;
}
/*在指定值的节点插入新节点*/
void LLInsertbyValue(Linkedlist* L, int val, int preval) {
    while (L) {
        if (L->val == preval) {
            Linkedlist* temp = LLCreateNode(val);
            temp->next = L->next;
            L->next = temp;
            return;
        }
        L = L->next;
    }
}
void LLDeletebyValue(Linkedlist* L, int val) {

    Linkedlist* cur = L;
    if (cur -> val == val && cur->next) {  // 删除头节点
        cur ->val = cur->next->val;
        cur->next = cur->next->next;
        return;
    }

    while (cur->next) {      // 删除目标节点
        if (cur->next->val == val) {
            Linkedlist* temp = cur->next;
            cur->next = temp->next;
            free(temp);
            return;
        }
        cur = cur->next;
    }
    return;                    // 没有目标节点
}

void LLprint(Linkedlist *L){
    Linkedlist *head = L;
    while(head){
        printf("%d ", head->val);
        head = head->next;
    }
    printf("\n");
}

int main() {
    Linkedlist* L = NULL;
    int num = 0;
    int val, preval;
    if (scanf("%d %d", &num, &val) != EOF) {
        L = LLCreateNode(val);
        int i = 1;

        while (i < num  && scanf("%d %d", &val, &preval) != EOF) {  // 插入节点
            LLInsertbyValue(L, val,  preval);
            i++;
        }

        if(scanf("%d", &val) != EOF){    // 删除节点
            LLDeletebyValue(L, val);
        }
        
        LLprint(L);        // 输出
    }
    return 0 ;
}