c140个最基本C语言代码，慢慢看吧

#include <stdio.h> #define TYPE struct stu #define LEN sizeof(struct stu) struct stu { int num; int age; struct stu *next; }; TYPE * creatlink(int n); TYPE * deletelink(TYPE * head,int num); TYPE * insertlink(TYPE * head,TYPE * pi); void printlink(TYPE * head); void destroylink( TYPE * head ); void main(void) { TYPE *head=NULL,*pnum=NULL; int n,num; /* 创建一个含 n 个节点的链表 */ printf("input number of node:"); scanf("%d",&n); head=creatlink(n); printlink(head); /* 删除链表中值为 num 的节点 */ printf("Input the deleted number:"); scanf("%d",&num); head=deletelink(head,num); printlink(head); /* 在链表中插入一个节点 */ printf("Insert a record\n"); pnum=(TYPE *)malloc(LEN); if(pnum==NULL) printf("Pointer is NULL--memory alloc fail!"); printf("Input the inserted number:"); scanf("%d",&pnum->num); printf("Input the inserted age:"); scanf("%d",&pnum->age); head=insertlink(head,pnum); printlink( head ); /* 销毁链表, 释放动态分配的内存 */ destroylink( head ); } /* 创建一个含 n 个节点的链表 */ TYPE * creatlink(int n) { TYPE *head=NULL, *pf, *pb; int i; for(i=0;i<n;i++) { pb=(TYPE *)malloc(LEN); printf("record %d\n",i); printf("input Number:"); scanf("%d",&pb->num); printf("input age:"); scanf("%d",&pb->age); if(i==0) pf=head=pb; else pf->next=pb; pb->next=NULL; pf=pb; } return(head); } /* 删除链表中值为 num 的节点 */ TYPE * deletelink(TYPE * head,int num) { TYPE *pf, *pb; if(head==NULL) { printf("\nempty list!\n"); return NULL; } pb=head; while (pb->num!=num && pb->next!=NULL) { pf=pb; pb=pb->next; } if(pb->num==num) { if(pb==head) head=pb->next; else pf->next=pb->next; free(pb); printf("The node is deleted\n"); } else printf("The node not been found!\n"); return head; } /* 在链表中插入一个节点 */ TYPE * insertlink(TYPE * head,TYPE * pi) { TYPE *pb, *pf; pb=head; if(head==NULL) { head=pi; pi->next=NULL; } else { while((pi->num > pb->num)&&(pb->next!=NULL)) { pf=pb; pb=pb->next; } if(pi->num <= pb->num) { if(head==pb) head=pi; else pf->next=pi; pi->next=pb; } else { pb->next=pi; pi->next=NULL; } } return head; } /* 打印链表中各节点信息 */ void printlink(TYPE * head) { printf("Number\t\tAge\n"); while(head!=NULL) { printf("%d\t\t%d\n",head->num,head->age); head=head->next; } } /* 销毁链表, 释放动态分配的内存 */ void destroylink(TYPE * head) { TYPE *p, *q; p = head; while( p != NULL ) { q = p->next; free(p); p = q; } }