02-线性结构2 一元多项式的乘法与加法运算 （20 分

#include<cstdio>
const int maxn = 2010;
int add[maxn]={0},mul1[maxn]={0},mul2[maxn];
int main(){
    int n,ex,coe;//coe 系数，ex指数 
    scanf("%d",&n);
    for(int i = 0; i < n; i++){
        scanf("%d%d",&coe,&ex);
        add[ex] += coe;
        mul1[ex] += coe;
    }
    scanf("%d",&n);
    for(int i = 0; i < n; i++){
        scanf("%d%d",&coe,&ex);
        add[ex] += coe;
        for(int j = 0; j < maxn; j++){
            if(mul1[j] != 0){
                mul2[j+ex] += coe*mul1[j];
            }
        }
    }
    int count1 = 0,count2 = 0;
    for(int i = 0; i < maxn; i++){
        if(add[i] != 0) count1++;
        if(mul2[i] != 0) count2++;
    }
    //printf("%d %d\n",count1,count2);
    if(count2 == 0) printf("0 0\n");
    else{
        for(int i = maxn; i >= 0; i--){
            if(mul2[i] != 0){
                printf("%d %d",mul2[i],i);
                count2--;
                if(count2 > 0) printf(" ");
                else printf("\n");
                }
            }
        }    
    if(count1 == 0) printf("0 0");
    else{
        for(int i = maxn; i >= 0; i--){
            if(add[i] != 0){
                printf("%d %d",add[i],i);
                count1--;
                if(count1 > 0) printf(" ");
            }            
        }
    }
    return 0;
}