简单的多项式相乘。
#include<iostream>
using namespace std;
const int iMax=5005;
double a[iMax]={0},b[iMax]={0},c[iMax]={0};
int main()
{
int n,m,i,j,alen,blen,index,count;
double val;
//freopen("C:\\Documents and Settings\\Administrator\\桌面\\input.txt","r",stdin);
scanf("%d",&n);
alen=blen=-1;
for(i=0;i<n;i++){
scanf("%d%lf",&index,&val);
a[index]=val;
if(alen==-1)
alen=index;
}
scanf("%d",&m);
for(i=0;i<m;i++){
scanf("%d%lf",&index,&val);
b[index]=val;
if(blen==-1)
blen=index;
}
for(i=0;i<=alen;i++){
for(j=0;j<=blen;j++){
c[i+j]+=a[i]*b[j];
}
}
count=0;
for(i=alen+blen;i>=0;i--)
if(c[i]!=0)
count++;
printf("%d",count);
for(i=alen+blen;i>=0;i--)
if(c[i]!=0)
printf(" %d %.1lf",i,c[i]);
return 0;
}