Fixes

Author: adamant-pwn

cp-algo/linalg/frobenius.hpp

@@ -52,17 +52,20 @@ namespace cp_algo::linalg {
         }
         // Find transform matrices while we're at it...
         if constexpr (mode == full) {
-            for(size_t i = 0; i < size(basis); i++) {
-                for(size_t j = i + 1; j < size(basis); j++) {
+            for(size_t i = 0; i < n; i++) {
+                for(size_t j = i + 1; j < n; j++) {
                     basis[i].reduce_by(basis[j]);
                 }
                 basis[i].normalize();
-                basis[i] = vec<base>(
-                    basis[i][std::slice(n, n, 1)]
-                ) * (base(1) / basis[i][i]);
             }
             auto T = matrix::from_range(basis_init);
             auto Tinv = matrix::from_range(basis);
+            std::ignore = Tinv.sort_classify(n);
+            for(size_t i = 0; i < n; i++) {
+                Tinv[i] = vec<base>(
+                    Tinv[i][std::slice(n, n, 1)]
+                ) * (base(1) / Tinv[i][i]);
+            }
             return std::tuple{T, Tinv, charps};
         } else {
             return charps;

cp-algo/linalg/matrix.hpp

@@ -28,9 +28,11 @@ namespace cp_algo::linalg {
 
         matrix& operator *=(base t) {for(auto &it: *this) it *= t; return *this;}
         matrix operator *(base t) const {return matrix(*this) *= t;}
+        matrix& operator /=(base t) {return *this *= base(1) / t;}
+        matrix operator /(base t) const {return matrix(*this) /= t;}
 
         // Make sure the result is matrix, not Base
-        matrix& operator*=(matrix const& t) {return *this = *this * t;}
+        matrix& operator *=(matrix const& t) {return *this = *this * t;}
 
         void read() {
             for(auto &it: *this) {
@@ -227,7 +229,7 @@ namespace cp_algo::linalg {
                 };
             }
         }
-    private:
+
         // To be called after a gaussian elimination run
         // Sorts rows by pivots and classifies
         // variables into pivots and free

verify/linalg/pow_fast.test.cpp

@@ -1,8 +1,7 @@
 // @brief Pow of Matrix (Frobenius)
 #define PROBLEM "https://judge.yosupo.jp/problem/pow_of_matrix"
 #pragma GCC optimize("Ofast,unroll-loops")
-#pragma GCC target("tune=native")
-#define CP_ALGO_MAXN 1 << 10
+#define CP_ALGO_MAXN 256
 #include "cp-algo/linalg/frobenius.hpp"
 #include <bits/stdc++.h>