add blazingio as a submodule

Author: adamant-pwn

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "blazingio"]
+	path = blazingio
+	url = https://github.com/purplesyringa/blazingio.git

blazingio

@@ -91,14 +91,14 @@ namespace cp_algo::math {
     template<typename modint>
     concept modint_type = std::is_base_of_v<modint_base<modint, typename modint::Int>, modint>;
     template<modint_type modint>
-    std::istream& operator >> (std::istream &in, modint &x) {
+    decltype(std::cin)& operator >> (decltype(std::cin) &in, modint &x) {
         typename modint::UInt r;
         auto &res = in >> r;
         x.setr(r);
         return res;
     }
     template<modint_type modint>
-    std::ostream& operator << (std::ostream &out, modint const& x) {
+    decltype(std::cout)& operator << (decltype(std::cout) &out, modint const& x) {
         return out << x.getr();
     }
 

cp-algo/number_theory/modint.hpp

@@ -1,8 +1,10 @@
 // @brief Convolution mod $10^9+7$
 #define PROBLEM "https://judge.yosupo.jp/problem/convolution_mod_1000000007"
 #pragma GCC optimize("Ofast,unroll-loops")
-#include "cp-algo/math/fft.hpp"
+#define CP_ALGO_CHECKPOINT
 #include <bits/stdc++.h>
+#include "blazingio/blazingio.min.hpp"
+#include "cp-algo/math/fft.hpp"
 
 using namespace std;
 using namespace cp_algo::math;
@@ -14,10 +16,12 @@ void solve() {
     int n, m;
     cin >> n >> m;
     vector<base, cp_algo::big_alloc<base>> a(n), b(m);
-    copy_n(istream_iterator<base>(cin), n, begin(a));
-    copy_n(istream_iterator<base>(cin), m, begin(b));
+    for(auto &x: a) {cin >> x;}
+    for(auto &x: b) {cin >> x;}
+    cp_algo::checkpoint("read");
     fft::mul(a, b);
-    ranges::copy(a, ostream_iterator<base>(cout, " "));
+    for(auto x: a) {cout << x << " ";}
+    cp_algo::checkpoint("write");
 }
 
 signed main() {