二十五岁时我们都一样愚蠢、多愁善感，喜欢故弄玄虚，可如果不那样的话，五十岁时也就不会如此明智。
标题：C示例程序更新循环链接列表中的项目
C示例程序更新循环链接列表中的项目
#include <stdio.h> #include <stdlib.h> struct node { int data; struct node *next; }; struct node *head = NULL; struct node *current = NULL; //insert link at the first location void insert(int data) { // Allocate memory for new node; struct node *link = (struct node*) malloc(sizeof(struct node)); link->data = data; link->next = NULL; // If head is empty, create new list if(head==NULL) { head = link; head->next = link; return; } current = head; // move to the end of the list while(current->next != head) current = current->next; // Insert link at the end of the list current->next = link; // Link the last node back to head link->next = head; } void update_data(int old, int new) { int pos = 0; if(head==NULL) { printf("Linked List not initialized"); return; } current = head; while(current->next!=head) { if(current->data == old) { current->data = new; printf("\n%d found at position %d, replaced with %d\n", old, pos, new); return; } current = current->next; pos++; } if(current->data == old) { current->data = new; printf("\n%d found at position %d, replaced with %d\n", old, pos, new); return; } printf("%d does not exist in the list\n", old); } //display the list void printList() { struct node *ptr = head; printf("\n[head] =>"); //start from the beginning while(ptr->next != head) { printf(" %d =>",ptr->data); ptr = ptr->next; } printf(" %d =>",ptr->data); printf(" [head]\n"); } int main() { insert(10); insert(20); insert(30); insert(1); insert(40); insert(56); printList(); update_data(56,11); printList(); return 0; }
