Title description
Polynomial multiplication is similar to 1002. 1002 is polynomial addition. Since I didn't understand how polynomial multiplication is calculated at the beginning, this question is actually very simple.
#include<cstdio>
using namespace std;
double A[1005],result[2005];
int main(){
int n;
scanf("%d",&n);
int x;
double y;
while(n--){
scanf("%d%lf",&x,&y);
A[x]=y;
}
scanf("%d",&n);
while(n--){
scanf("%d%lf",&x,&y);
for(int i=0;i<1005;i++)
result[x+i]+=A[i]*y;
}
int num=0;
for(int i=0;i<2005;i++){
if(result[i]!=0)
num++;
}
printf("%d",num);
for(int i=2005;i>=0;--i){
if(result[i]!=0)
printf(" %d %.1f",i,result[i]);
}
}