一元多项式加减计算器

#include "iostream.h"
#include "malloc.h"

typedef struct{                 //多项式结构体的元素的结构体；
int xishu;
int zhishu;
}xiangshi;

typedef struct{                 //多项式结构体；
xiangshi *top;
int num;
}shizi;



void init(shizi &a,int m){
int i;
a.num=m;
a.top=(xiangshi*)malloc(m*sizeof(xiangshi));
for(i=0;i<a.num;i++){
cout<<"第"<<i+1<<"项的指数及系数输入：";
cin>>a.top[i].zhishu;
cout<<"                       ";
cin>>a.top[i].xishu;
}
}

void disp(shizi &a){
int i;
cout<<"f(x)=";

for(i=0;i<a.num;i++){

if(i!=(a.num-1))
cout<<a.top[i].xishu<<"*(x^"<<a.top[i].zhishu<<")+";
else
cout<<a.top[i].xishu<<"*(x^"<<a.top[i].zhishu<<")"<<endl;
}
}




void jiafa(shizi &a,shizi &b,shizi &c){
int i,j;
int m;
c.num=b.num;
c.top=(xiangshi*)malloc(c.num*sizeof(xiangshi));
for(i=0;i<b.num;i++){
c.top[i].xishu=b.top[i].xishu;
c.top[i].zhishu=b.top[i].zhishu;
}
for(j=0;j<a.num;j++){                                     //a循环；
m=1;
for(i=0;i<b.num;i++){                                 //b循环；
if(a.top[j].zhishu==b.top[i].zhishu)
c.top[i].xishu+=a.top[j].xishu;
else
m++;
}
if(m==b.num){