Submission #1438733

---

Source Code Expand

#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(a, b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define pb push_back
#define show(x) cout <<#x<<" = "<<(x)<<endl
#define spair(p) cout <<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout <<" "<<kbrni;cout<<endl

using namespace std;

typedef pair<int,int>P;
typedef complex<double>C;

const int MAX_N = 100005;
const double PI = 4*atan(1.0);

vector<C> FFT(double theta, const vector<C>& a){
    int n = (int)a.size();
    vector<C> ret = a;
    for(int m=n; m>=2; m>>=1){
        int mh = m>>1;
        rep(i,mh){
            C w = exp(i*theta*C(0,1));
            for(int j=i; j<n; j+=m){
                int k = j+mh;
                C x = ret[j] - ret[k];
                ret[j] += ret[k];
                ret[k] = w*x;
            }
        }
        theta *= 2;
    }
    int i=0;
    for(int j=1; j<n-1; j++){
        for(int k=n>>1; k>(i^=k); k>>= 1){

        }
        if(j < i) swap(ret[i], ret[j]);
    }
    return ret;
}

//畳み込み
template<class T>
vector<T> Convolution(const vector<T> &lhs, const vector<T> &rhs){
    int n = 1;
    while(n < (int)max(lhs.size(), rhs.size())*2){
        n <<= 1;
    }
    vector<C> temp1(n);
    vector<C> temp2(n);
    for(int i=0; i<n/2; i++){
        if(i < (int)lhs.size()){
            temp1[i] = C(lhs[i], 0);
        }
        if(i < (int)rhs.size()){
            temp2[i] = C(rhs[i], 0);
        }
    }
    //FFTにかけて周波数分解
    temp1 = FFT(2.0*PI/n, temp1);
    temp2 = FFT(2.0*PI/n, temp2);
    //周波数同士で掛け算
    rep(i,n){
        temp1[i] *= temp2[i];
    }
    //逆FFTをかけて元に戻す
    temp1 = FFT(-2.0*PI/n, temp1);
    vector<T> ret(n);
    rep(i,n){
        ret[i] = (T)(temp1[i].real()/n + 0.5); //T=intの時用
    }
    return ret;
}

int main()
{
    int n;
    cin >> n;
    ios::sync_with_stdio(false);
    cin.tie(0);
    vector<int> a(n),b(n);
    rep(i,n){
        cin >> a[i] >> b[i];
    }
    vector<int> res = Convolution(a,b);
    cout << 0 << endl;
    rep(i,2*n-1){
        cout << res[i] << endl;
    }
}

Submission Info

Judge Result