这为啥运行结果是空的啊，编译也没问题

 
#include <stdio.h>
#include <stdlib.h>
struct space{
        int xishu;
        int zhishu;
        struct space *next;
};
struct space* create();
void print(struct space *p);
struct space* mul(struct space *p1,struct space *p2);
struct space* add(struct space *p1,struct space *p2);
void attach(int c,int e,struct space **L2);
int main(){
    struct space *p1;
    struct space *p2;
    struct space *p3;
    struct space *p4;
    p1 = create();
    p2 = create();
    p3 = mul(p1,p2);
    p4 = add(p1,p2);
    print(p3);
    print(p4);
    return 0;
}
struct space* create(){ //创建链表 
    int n,i;
    scanf("%d",&n);
    struct space *head;
    struct space *rom;
    rom=(struct space*)malloc(sizeof(struct space));
    head=rom;
    while(n--){
    rom=rom->next;
    rom=(struct space*)malloc(sizeof(struct space));
    scanf("%d %d",&rom->xishu,&rom->zhishu);
    }
    rom->next=NULL;
    return head;
}
struct space* mul(struct space *p1,struct space *p2){ //两个多项式相乘 
    struct space *L,*front1,*middle1,*middle2;
    L=(struct space*)malloc(sizeof(struct space));
    L->next=NULL;
    front1=L;
    p1=p1->next;
    p2=p2->next;
    middle1=p1;
    L=L->next;
    for(;middle1;middle1=middle1->next){
        middle2=p2;
        for(;middle2;middle2=middle2->next){
    L->xishu=(middle1->xishu)+(middle2->xishu);
    L->zhishu=(middle1->zhishu)*(middle2->zhishu);
    L->next = NULL;
    L=L->next;
    L=(struct space*)malloc(sizeof(struct space));
    L->next = NULL;
        }
    }
    return front1;
}
struct space* add(struct space *p1,struct space *p2){ //两个多项式相加 
    struct space *L2,*front2;
    L2=(struct space*)malloc(sizeof(struct space));
    L2->next=NULL;
    front2=L2;
    p1=p1->next;
    p2=p2->next;
    while(p1&&p2){
    if(p1->zhishu>p2->zhishu){
        attach(p1->xishu,p1->zhishu,&L2);
        p1=p1->next;
    }else if(p2->zhishu>p2->zhishu){
        attach(p2->xishu,p2->zhishu,&L2);
        p2=p2->next;
    }else{
        if(p2->xishu+p1->xishu){
            attach(p1->xishu+p2->xishu,p1->zhishu,&L2);
            p2=p2->next;
            p1=p1->next;
        }else{
            ;
        }
    }
}
        L2->next=p1?p1:p2;
        return front2;
}
void attach(int c,int e,struct space **L2){ //将系数、指数插到新链表里 
    struct space *p;
    p=(struct space*)malloc(sizeof(struct space));
    p->ishu=c;
    p->zhishu=e;
    (*L2)->next=p;
    (*L2)=p;
}
void print(struct space *p){ //打印 
    p=p->next;
    while(p){
        printf("%d %d",p->xishu,p->zhishu);
        if(p->next){
        printf(" ");
        }
        p=p->next;
    }
}
 

```c

//代码太多了，眼会花，先改这个创建的函数，改完还有错就继续来
struct space* create(){ //创建链表 
    int n,i;
    scanf("%d",&n);
    struct space *head;
    struct space *rom;
    head=(struct space*)malloc(sizeof(struct space));
    rom=head;
    while(n--){
    rom->next=(struct space*)malloc(sizeof(struct space));
    rom=rom->next;
    scanf("%d %d",&rom->xishu,&rom->zhishu);
    }
    rom->next=NULL;
    return head;
}

```

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

struct space{
        int xishu;
        int zhishu;
        struct space *next;
};
struct space* create();
void print(struct space *p);
struct space* mul(struct space *p1,struct space *p2);
struct space* add(struct space *p1,struct space *p2);
struct space* attach(int c,int e,struct space *L2);
    
int main(){
    struct space *p1;
    struct space *p2;
    struct space *p3;
    struct space *p4;
    p1 = create();
    p2 = create();
    p3 = mul(p1,p2);
    p4 = add(p1,p2);
    print(p3);
    print(p4);
    return 0;
}

struct space* create(){
    int n,i;
    scanf("%d",&n);
    struct space *head;
    struct space *rom;
    head=(struct space*)malloc(sizeof(struct space));
    rom=head;
    while(n--){
    rom->next=(struct space*)malloc(sizeof(struct space));
    rom=rom->next;
    scanf("%d %d",&rom->xishu,&rom->zhishu);
    }
    rom->next=NULL;
    return head;
}

struct space* mul(struct space *p1,struct space *p2){ //两个多项式相乘 
    struct space *L,*front1,*middle1,*middle2;
    L=(struct space*)malloc(sizeof(struct space));
    L->next=NULL;
    front1=L;
    p1=p1->next;
    p2=p2->next;
    middle1=p1;
    L=L->next;
    for(;middle1;middle1=middle1->next){
        middle2=p2;
        for(;middle2;middle2=middle2->next){
    L->xishu=(middle1->xishu)+(middle2->xishu);
    L->zhishu=(middle1->zhishu)*(middle2->zhishu);
    L=L->next;
    L=(struct space*)malloc(sizeof(struct space));
        }
    }
    L->next=NULL;
    return front1;
}

struct space* add(struct space *p1,struct space *p2){ //两个多项式相加 
    struct space *L2,*front2;
    L2=(struct space*)malloc(sizeof(struct space));
    L2->next=NULL;
    front2=L2;
    p1=p1->next;
    p2=p2->next;
    while(p1&&p2){
    if(p1->zhishu>p2->zhishu){
        L2=attach(p1->xishu,p1->zhishu,L2);
        p1=p1->next;
    }else if(p2->zhishu>p2->zhishu){
        L2=attach(p2->xishu,p2->zhishu,L2);
        p2=p2->next;
    }else{
        if(p2->xishu+p1->xishu){
            L2=attach(p1->xishu+p2->xishu,p1->zhishu,L2);
            p2=p2->next;
            p1=p1->next;
        }else{
            L2=attach(0,0,L2);
        }
    }
}
        L2->next=p1?p1:p2;
        return front2;
}
struct space* attach(int c,int e,struct space* L2){ //将系数、指数插到新链表里 
    struct space *p;
    struct space *front3;
    front3  = L2;
    p=(struct space*)malloc(sizeof(struct space));
    p->xishu=c;
    p->zhishu=e;
    L2->next=p;
    L2=p;
    L2->next=NULL; 
    return front3;
}
void print(struct space *p){ //打印 
    struct space* m = p->next;
    while(m){
        printf("%d %d",m->xishu,m->zhishu);
        if(m->next){
        printf(" ");
        }
        m=m->next;
    }
}

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

struct space{
        int xishu;
        int zhishu;
        struct space *next;
};

struct space* create();
void print(struct space *p);
struct space* add(struct space *p1,struct space *p2);
struct space* mul(struct space* p1,struct space*p2);

int main(){
    struct space *p1;
    struct space *p2;
    struct space *p3;
    struct space *p4;
    p1 = create();
    p2 = create();
    p4 = mul(p1,p2);
    p3 = add(p1,p2);
    print(p3);
    print(p4);
    return 0;
}

struct space* create(){//wode
    int n;
    scanf("%d",&n);
    struct space *head;
    struct space *rom;
    head=(struct space*)malloc(sizeof(struct space));
    rom=head;
    while(n--){
    rom->next=(struct space*)malloc(sizeof(struct space));
    rom=rom->next;
    scanf("%d%d",&(rom->xishu),&(rom->zhishu));
    }
    rom->next=NULL;
    return head;
}

struct space* add(struct space* p1,struct space*p2){
    struct space* L1;
    L1=(struct space*)malloc(sizeof(struct space));
    L1->next=NULL;
    struct space* top;
    struct space* a1;
    struct space* a2;
    top=L1;
    a1=p1->next;
    a2=p2->next;
    while(a1&&a2){
        if(a1->zhishu>a2->zhishu){
            struct space* middle=(struct space*)malloc(sizeof(struct space));
            middle->next=NULL;
            middle->xishu=a1->xishu;
            middle->zhishu=a1->zhishu;
            top->next=middle;
            top=middle;
            middle->next=NULL;
            a1=a1->next;
        }else if(a1->zhishu<a2->zhishu){
            struct space* middle=(struct space*)malloc(sizeof(struct space));
            middle->next=NULL;
            middle->xishu=a2->xishu;
            middle->zhishu=a2->zhishu;
            top->next=middle;
            top=middle;
            middle->next=NULL;
            a2=a2->next;
        }else{
            if(a1->xishu+a2->xishu){
                struct space* middle=(struct space*)malloc(sizeof(struct space));
                middle->next=NULL;
                middle->xishu=a2->xishu+a1->xishu;
                middle->zhishu=a2->zhishu;
                top->next=middle;
                top=middle;
                middle->next=NULL;
                a1=a1->next;
                a2=a2->next;
            }
        }
    }
    while(a1){
        struct space* middle=(struct space*)malloc(sizeof(struct space));
            middle->next=NULL;
            middle->xishu=a1->xishu;
            middle->zhishu=a1->zhishu;
            top->next=middle;
            top=middle;
    middle->next=NULL;
            a1=a1->next;
    }
    while(a2){
        struct space* middle=(struct space*)malloc(sizeof(struct space));
            middle->next=NULL;
            middle->xishu=a2->xishu;
            middle->zhishu=a2->zhishu;
            top->next=middle;
            top=middle;
            middle->next=NULL;
            a2=a2->next;
    }
    top->next=NULL;
    return L1;
}

void print(struct space *p){ //打印 
    struct space* m = p->next;
    while(m){
        printf("%d %d",m->xishu,m->zhishu);
        if(m->next){
        printf(" ");
        }else{
        printf("\n");
        }
        m=m->next;
    }
}

struct space* mul(struct space* p1,struct space*p2){
    struct space* p5;
    struct space* L3;
    L3=(struct space*)malloc(sizeof(struct space));
    L3->next=NULL;
    struct space* p55;
    struct space* p66;
    struct space* pn;
    struct space* phead;
    p55=p1->next;
    p66=p2->next;
    if(p1&&p2){
    for(p55=p1->next;p55;p55=p55->next){
        p5=(struct space*)malloc(sizeof(struct space));
        p5->next=NULL;
        phead=p5;
        for(p66=p2->next;p66;p66=p66->next){
    pn=(struct space*)malloc(sizeof(struct space));
    pn->xishu=p55->xishu*p66->xishu;
    pn->zhishu=p55->zhishu+p66->zhishu;
    phead->next=pn;
    phead=pn;
        }
        L3=add(L3,p5);
        free(p5);
    }
}
    return L3;
}