为什么输入一组数据就自动结束了

Question

链表

#include<stdio.h>
#include<stdlib.h>
#include<string.h> 
struct students{
    int num;
    char name[20];
    int score;
    struct students *next;
}; 
int main()
{
    int num,score;
    char name[20];
    int size=sizeof(struct students);
    struct students *head,*tail,*p;
    head=tail=NULL;
    scanf("%d%s%d",&num,name,&score);
    while(num!=0){
        p=(struct students*)malloc(size);
        p->num=num;
        strcpy(p->name,name);
        p->score=score;
        p->next=NULL;
        if(head=NULL){
            head=p;
        }
        else{
            tail->next=p;
        }
        tail=p;
        scanf("%d%s%d",&num,name,&score);
    }
    scanf("%d",&score);
    struct students *ptr;
    for(ptr=head;ptr!=NULL;ptr=ptr->next){
        if(ptr->score>score){
            printf("%d %s %d\n",&ptr->num,ptr->name,&ptr->score);
        }
    }
    
    

    
    
    return 0;
}

Answer 1

24行里的if少一个等号