[模板] ntt模板

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

const int mod = 998244353;
const int maxn = 100010;
const int g = 3;

int n, m;
int rev[maxn*4];
int w_a[maxn*4], w_b[maxn*4], w_c[maxn*4];

int (int x, int y) {
    int ret = 1;
    while (y) {
        if (y & 1) {
            ret = 1LL*ret*x%mod;
        }
        x = 1LL*x*x%mod;
        y >>= 1;
    }
    return ret;
}

void calrev(int l) {
    rev[0] = 0;
    for (int i = 1; i < (1<<l); i++) {
        rev[i] = (rev[i>>1] >> 1);
        if (i & 1) rev[i] |= (1<<(l-1));
    }
}

void ntt(int *a, int t, int ty) {
    int len = 1<<t;
    for (int i = 0; i < len; i++) {
        if (rev[i] > i)
            swap(a[i], a[rev[i]]);
    }
    for (int l = 2; l <= len; l <<= 1) {
        int wn = qpow(g, (mod-1)/l);
        for (int s = 0; s < len; s += l) {
            int w = 1;
            for (int i = s; i < (s + (l >> 1)); i++) {
                int v1 = a[i], v2 = 1LL*a[i+(l>>1)]*w%mod;
                a[i] = (v1+v2) % mod;
                a[i+(l>>1)] = (v1-v2+mod)%mod;
                w = 1LL*w*wn%mod;
            }
        }
    }
    if (ty == -1) {
        for (int i = 1; i < len/2; i++) {
            swap(a[i], a[len-i]);
        }
        int r = qpow(len, mod-2);
        for (int i = 0; i < len; i++) {
            a[i] = 1LL*a[i]*r%mod;
        }
    }
}

int main() {
    scanf("%d%d", &n, &m);
    for (int i = 0; i <= n; i++)
        scanf("%d", &w_a[i]);
    for (int i = 0; i <= m; i++) 
        scanf("%d", &w_b[i]);
    int l = 0;
    while ((1<<l) < n+m+1) l ++;
    calrev(l);
    ntt(w_a, l, 1); ntt(w_b, l, 1);
    for (int i = 0; i < (1<<l); i++)
        w_c[i] = 1LL*w_a[i]*w_b[i]%mod;
    ntt(w_c, l, -1);
    for (int i = 0; i <= n+m; i++) {
        printf("%d ", w_c[i]);
    } 
    printf("n");
    return 0;
}