多项式加法

这个程序运行不了跪求各位帮帮我改一下或者告诉我哪里出问题也可以! 急!拜托了!#include<stdio.h>#include<malloc.h>typedef struct lnode{int coef;int expn;struct lnode *next;}lnode;typedef lnode * plnode;void print(plnode l){while(l!=NULL){if((l->coef!=0)&&(l->expn!=0))printf("%dx%d",l->coef,l->expn);if(l->expn==0)printf("%d",l->coef);if((l->next!=NULL)&&(l->next->coef>0)) printf("+"); if((l->next!=NULL)&&(l->next->coef<0)) printf("-"); l=l->next;}printf("\n");}void create(plnode &l){int i=1,m;plnode head,p;printf("请输入项数：");scanf("%d",&m);head=(plnode)malloc(sizeof(lnode));p=head;head->next=NULL;while(i<=m){l=(plnode)malloc(sizeof(lnode));printf("请输入多项式系数：");scanf("%d",&l->coef);printf("请输入多项式指数：");scanf("%d",&l->expn);head->next=l;l->next=NULL;head=head->next;i++;}l=p->next;free(p);printf("多项式：\n");print(l);}void add(plnode &la,plnode &lb,plnode &lc) {plnode r,s,p;r=la;s=lb;p=lc;while(r&&s){lc->next=NULL;lc=lc->next;if(r->expn==s->expn){lc->coef=r->coef+s->coef;lc->expn=r->expn;r=r->next;s=s->next;}else{if(s->expn>r->expn){lc=r;r=r->next;}else {lc=s;s=s->next;}}}if(s!=NULL)lc->next=s;if(r!=NULL)lc->next=r;lc=p->next;free(p);printf("多项式A+B：\n");print(lc);}void cheng(plnode &la,plnode &lb,plnode &ld) {plnode r,s;r=la;s=lb;while(r!=NULL){while(s!=NULL){ld=(plnode)malloc(sizeof(lnode));ld->coef=(r->coef)*(s->coef);ld->expn=(r->expn)+(s->expn);s=s->next;ld=ld->next;}s=lb;r=r->next;}printf("多项式A*B：\n");print(ld);}void main(){plnode la,lb,lc,ld;printf("请输入多项式A:\n");la=(plnode)malloc(sizeof(lnode));create(la);printf("请输入多项式B:\n");lb=(plnode)malloc(sizeof(lnode));create(lb);lc=(plnode)malloc(sizeof(lnode));add(la,lb,lc);ld=(plnode)malloc(sizeof(lnode));cheng(la,lb,ld);free(la);free(lb);free(lc);free(ld);}2008-4-5 01:36最佳答案你这个程序写得不是一般的乱……main里ld=(plnode)malloc(sizeof(lnode));而cheng(la,lb,ld);里ld=(plnode)malloc(sizeof(lnode));又做了一遍，之前的内存也没释放，变脏了……同样，那个在main里的la也变脏了，你根本没用。

按你的写法，cheng也应该像add里一样void cheng(plnode &la,plnode &lb,plnode &ld){plnode r,s,t;r=la;s=lb;t=ld;//加了个twhile(r!=NULL){while(s!=NULL){ld->next=(plnode)malloc(sizeof(lnode));//这里改了ld=ld->next;//这里改了ld->coef=(r->coef)*(s->coef);ld->expn=(r->expn)+(s->expn);//这里删除了s=s->next;}s=lb;r=r->next;}ld = t->next;free(t);//这2行模仿你add函数。

不明白这么做是为了什么。

printf("多项式A*B：\n");print(ld);}add改这样：void add(plnode &la,plnode &lb,plnode &lc) {plnode r,s,p;r=la;s=lb;p=lc;while(r&&s){lc->next=(plnode)malloc(sizeof(lnode));lc=lc->next;if(r->expn==s->expn){lc->coef=r->coef+s->coef;lc->expn=r->expn;r=r->next;s=s->next;}else{if(s->expn>r->expn){lc=r;r=r->next;}else{lc=s;s=s->next;}}}if(s!=NULL)lc->next=s;if(r!=NULL)lc->next=r;lc=p->next;free(p);printf("多项式A+B：\n");print(lc);}太乱了，准备重给你写一下……以下是代码#include<stdio.h>#include<malloc.h>typedef struct lnode{int coef;int expn;struct lnode *next;}lnode;typedef lnode * plnode;void print(plnode l){l=l->next;while(l!=NULL){if((l->coef!=0)&&(l->expn!=0))printf("%dx^%d",l->coef,l->expn);if(l->expn==0)printf("%d",l->coef);if((l->next!=NULL)&&(l->next->coef>0))printf(" +");if((l->next!=NULL)&&(l->next->coef<0))printf(" -");l=l->next;}printf("\n");}void create(plnode &l){int i,m;plnode rear;//尾指针printf("请输入项数：");scanf("%d",&m);l = (plnode)malloc(sizeof(lnode));//带头结点的链表。

l->coef = 0;l->expn = 0;l->next = NULL;//头结点的值全为0rear = l;i = 0;while ( i < m ){rear->next = ( plnode )malloc( sizeof(lnode) );rear = rear->next;rear->next = NULL;printf( "请输入多项式系数：" );scanf( "%d", &rear->coef);printf( "请输入多项式指数：" );scanf( "%d", &rear->expn);i++;}}void add( plnode la, plnode lb, plnode &lc)//如果la和lb只是参数，不需要让它们返回{plnode rear,r,s;lc = ( plnode )malloc( sizeof(lnode) );//带头结点的链表。

lc->coef = 0;lc->expn = 0;lc->next = NULL;//头结点的值全为0rear = lc;r = la->next;s = lb->next;while ( r!=NULL && s!=NULL ){rear->next = (plnode)malloc(sizeof(lnode));rear = rear->next;rear->next = NULL;if( r->expn == s->expn ){rear->coef = r->coef+s->coef;rear->expn = r->expn;r = r->next;s = s->next;}else{if(s->expn>r->expn){//以前你写的就是指过去了。