1009 Product of Polynomials (25)

跟1002很像的一个题，就是从加法改成了乘法。

#include <cstdio>#include <vector>#include <string>#include <cstring>#include <cstdlib>#include <iostream>#include <algorithm>#define INF 0x3fffffffusing namespace std;int main(){    double a[1005],b[1005],c[2005];    memset(a,0,sizeof(a));    memset(b,0,sizeof(b));    memset(c,0,sizeof(c));    int n,j;    double k;    cin>>n;    while(n--)    {        cin>>j>>k;        a[j]=k;    }    cin>>n;    while(n--)    {        cin>>j>>k;        b[j]=k;    }    for (int i=0;i<1001;i++)        for (int j=0;j<1001;j++)            c[i+j]=c[i+j]+a[i]*b[j];    int cnt=0;    vector<int> sx;    for (int i=2002;i>=0;i--)    {        if (c[i]!=0)        {            cnt++;            sx.push_back(i);        }    }    cout<<cnt;    for (int i=0;i<sx.size();i++)    {        cout<<' '<<sx[i];        printf(" %.1f",c[sx[i]]);    }}