poj1996

多项式计算，有点像母函数，注意最后要判断最高次项是否为0。

#include <cstdio>
#include <cstring>
using namespace std;

#define MAX_NUM 105

int a_num, b_num;
int a[MAX_NUM], b[MAX_NUM];
int c[MAX_NUM * MAX_NUM];
int poly[2][MAX_NUM * MAX_NUM];
int poly_num;

void input()
{
    scanf("%d%d", &a_num, &b_num);
    for (int i = 0; i <= a_num; i++)
        scanf("%d", &a[i]);
    for (int i = 0; i <= b_num; i++)
        scanf("%d", &b[i]);
}

void add_c(int poly[], int a)
{
    for (int i = 0; i <= poly_num; i++)
        c[i] += a * poly[i];
}

void add_poly(int last[], int next[])
{
    memset(next, 0, sizeof(int) * MAX_NUM * MAX_NUM);
    for (int i = 0; i <= b_num; i++)
    {
        for (int j = 0; j <= poly_num; j++)
            next[i + j] += b[i] * last[j];
    }
    poly_num += b_num;
}

void work()
{
    memset(c, 0, sizeof(c));
    for (int i = 0; i <= b_num; i++)
    {
        poly[1][i] = b[i];
    }
    poly_num = b_num;
    c[0] = a[0];
    add_c(poly[1], a[1]);
    for (int i = 2; i <= a_num; i++)
    {
        add_poly(poly[(i - 1) & 1], poly[i & 1]);
        add_c(poly[i & 1], a[i]);
    }
    while (c[poly_num] == 0)
        poly_num--;
    printf("%d", c[0]);
    for (int i = 1; i <= poly_num; i++)
        printf(" %d", c[i]);
    puts("");
}

int main()
{
    int case_num;
    scanf("%d", &case_num);
    for (int i = 0; i < case_num; i++)
    {
        input();
        work();
    }
}