题解 | #从单向链表中删除指定值的节点#

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<malloc.h>
#include<stddef.h>
struct node{
	struct node * next;
	int data;
};
struct link{
	struct node * headnode;
	int length;
};
void enlink_head(struct node * p,int b,int a){
	struct node * t=p;
	struct node *s=(struct node*)malloc(sizeof(struct node));
	s->next=NULL;
	s->data=a;
	while(1){
		if(t->data==b){
			s->next=t->next;
			t->next=s;
			//printf("did insert\n");
			break;
		}else if(p->next!=NULL){
			t=t->next;
			//printf("search for the tag\n");
		}else{
			//printf("invalid input!\n");
			break;
		}
	}
}
void delnode(struct node *t,int a){
	struct node * p=t;
	struct node * s;
	int flag=1;
	while(1){
		if(flag==1&&p->data==a){
			//printf("%d \n",t->data);
			t=t->next;
			//printf("%d \n",t->data);
			p=t;
			flag=0; 
		}else if(p->data!=a&&p->next!=NULL){
			s=p;
			p=p->next;
			//printf("researching\n"); 
		}else if(p->data==a){
			//printf("deleting\n");
			s->next=p->next;
			if(p->next!=NULL){
				//printf("continue searching\n");
				p=p->next;	
			}
		}else{
			//printf("did\n");
			break;
		}
	}
}
void printlink(struct link l){
	struct node * p=l.headnode;
	while(1){
		printf("%d ",p->data);
		if(p->next!=NULL){
		p=p->next;}else{break;}
	}
}
int main(){
	struct link l1;
	int temp,tag,delnum;
	int flag=0;
	//struct node * empty=NULL;
	//empty=l1.headnode;
	//if(empty!=NULL){printf("NULL可以经判断是否等于NUUL来完成条件判断\n"); 
	//}else{printf("buke");
	//}
	while(1){
		if(flag==0){
			scanf("%d",&temp);
			l1.length=temp;
			flag++;
			//printf("flag=%d\n",flag);
			continue;
		}else if(flag==1){
			scanf("%d",&temp);
			struct node *h=(struct node*)malloc(sizeof(struct node));
			l1.headnode=h;
			l1.headnode->next=NULL;
			l1.headnode->data=temp;
			flag++;
			//printf("flag=%d\n",flag);
			//printf("%d",l1.headnode->data);
			continue;
		}else if(flag<=l1.length){
			scanf("%d",&temp);
			scanf("%d",&tag);
			enlink_head(l1.headnode,tag,temp);
			//printlink(l1.headnode);
			flag++;
			//printf("flag=%d\n",flag);
			//printf("2\n");
			continue; 
		}else if(flag==l1.length+1){
			//printf("%d",l1.length);
			scanf("%d",&delnum);
			if(l1.headnode->data==delnum){
				l1.headnode=l1.headnode->next;
			}
			//printf("find the num to del %d\n",delnum);
			delnode(l1.headnode,delnum);
			//printf("%d \n",l1.headnode->data);
			//printf("3\n");
			//printf("exit\n");
			break;
		}else{
			printf("erro");
			break;
		}	
	}
	printlink(l1);
	return 0;
}