interpolation + pow tests, adjust "magic"

Author: adamant-pwn

cp-algo/math/common.hpp

@@ -8,7 +8,7 @@ namespace cp_algo::math {
 #else
     const int maxn = 1 << 19;
 #endif
-    const int magic = 250; // threshold for sizes to run the naive algo
+    const int magic = 128; // threshold for sizes to run the naive algo
 
     auto bpow(auto const& x, int64_t n, auto const& one, auto op) {
         if(n == 0) {

cp-algo/math/fft.hpp

@@ -279,7 +279,7 @@ namespace cp_algo::math::fft {
 
     template<typename base>
     void mul(std::vector<base> &a, std::vector<base> const& b) {
-        if(std::min(a.size(), b.size()) < 1) {
+        if(std::min(a.size(), b.size()) < magic) {
             mul_slow(a, b);
             return;
         }

verify/poly/inter.test.cpp

@@ -0,0 +1,30 @@
+// @brief Polynomial Interpolation
+#define PROBLEM "https://judge.yosupo.jp/problem/polynomial_interpolation"
+#include "cp-algo/math/poly.hpp"
+#include <bits/stdc++.h>
+
+using namespace std;
+using namespace cp_algo::math;
+
+const int mod = 998244353;
+using base = modint<mod>;
+using polyn = poly_t<base>;
+
+void solve() {
+    int n;
+    cin >> n;
+    vector<base> x(n), y(n);
+    copy_n(istream_iterator<base>(cin), n, begin(x));
+    copy_n(istream_iterator<base>(cin), n, begin(y));
+    polyn::inter(x, y).print(n);
+}
+
+signed main() {
+    //freopen("input.txt", "r", stdin);
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    int t = 1;
+    while(t--) {
+        solve();
+    }
+}

verify/poly/pow.test.cpp

@@ -0,0 +1,30 @@
+// @brief Pow of Power Series
+#define PROBLEM "https://judge.yosupo.jp/problem/pow_of_formal_power_series"
+#include "cp-algo/math/poly.hpp"
+#include <bits/stdc++.h>
+
+using namespace std;
+using namespace cp_algo::math;
+
+const int mod = 998244353;
+using base = modint<mod>;
+using polyn = poly_t<base>;
+
+void solve() {
+    int n;
+    int64_t m;
+    cin >> n >> m;
+    vector<base> a(n);
+    copy_n(istream_iterator<base>(cin), n, begin(a));
+    polyn(a).pow(m, n).print(n);
+}
+
+signed main() {
+    //freopen("input.txt", "r", stdin);
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    int t = 1;
+    while(t--) {
+        solve();
+    }
+}