From 0bf782cd079910151614fb1ff9269e904fe8bda2 Mon Sep 17 00:00:00 2001
From: ypodlesov <ypodlesov@gmail.com>
Date: Sun, 19 May 2024 13:56:06 +0000
Subject: [PATCH] Add reordering function.

---
 matrix_powers_mv/matrix_powers_mv.cpp | 15 +++++++++++++--
 matrix_powers_mv/matrix_powers_mv.h   |  2 +-
 matrix_powers_mv/test.cpp             | 23 +----------------------
 3 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/matrix_powers_mv/matrix_powers_mv.cpp b/matrix_powers_mv/matrix_powers_mv.cpp
index 20cf8e8..77c6c72 100644
--- a/matrix_powers_mv/matrix_powers_mv.cpp
+++ b/matrix_powers_mv/matrix_powers_mv.cpp
@@ -1,6 +1,8 @@
 #include "matrix_powers_mv.h"
+#include <cstdint>
+#include <cstring>
 
-int ReorderMatrix(const SparseMatrix<double>& sp_matrix) {
+bool ReorderMatrix(SparseMatrix<double>& sp_matrix) {
     SparseMatrix<double> a_no_diag;
     sp_matrix.RemoveDiag(a_no_diag);
     idx_t* perm = new idx_t[a_no_diag.row_cnt_];
@@ -20,7 +22,16 @@ int ReorderMatrix(const SparseMatrix<double>& sp_matrix) {
         , perm
         , iperm
     );
-    return result;
+    if (result != METIS_OK) {
+        return false;
+    }
+    for (int64_t i = 0; i < sp_matrix.row_cnt_; ++i) {
+        int64_t cur_row_cnt = sp_matrix.i_a_[i + 1] - sp_matrix.i_a_[i];
+        std::memcpy(&sp_matrix.data_[sp_matrix.i_a_[i]], &sp_matrix.data_[sp_matrix.i_a_[perm[i]]], cur_row_cnt * sizeof(double));
+        std::memcpy(&sp_matrix.j_a_[sp_matrix.i_a_[i]], &sp_matrix.j_a_[sp_matrix.i_a_[perm[i]]], cur_row_cnt * sizeof(int64_t));
+        sp_matrix.i_a_[i] = sp_matrix.i_a_[perm[i]];
+    }
+    return true;
 }
 
 void MatrixPowersMV(const SparseMatrix<double>& /* sp_matrix */, const Vector<double>& /* x */, const Vector<Vector<double>*>& /* res */) {
diff --git a/matrix_powers_mv/matrix_powers_mv.h b/matrix_powers_mv/matrix_powers_mv.h
index 16a4836..fe9e382 100644
--- a/matrix_powers_mv/matrix_powers_mv.h
+++ b/matrix_powers_mv/matrix_powers_mv.h
@@ -4,5 +4,5 @@
 #include <sparse_matrix.h>
 #include <vector.h>
 
-int ReorderMatrix(const SparseMatrix<double>& sp_matrix);
+bool ReorderMatrix(SparseMatrix<double>& sp_matrix);
 void MatrixPowersMV(const SparseMatrix<double>& sp_matrix, const Vector<double>& x, const Vector<Vector<double>*>& res);
\ No newline at end of file
diff --git a/matrix_powers_mv/test.cpp b/matrix_powers_mv/test.cpp
index 6747b27..2f17d63 100644
--- a/matrix_powers_mv/test.cpp
+++ b/matrix_powers_mv/test.cpp
@@ -21,29 +21,8 @@ static void Test(const uint32_t n) {
         fstream >> a;
         fstream.close();
         REQUIRE(a.data_);
-        SparseMatrix<double> a_no_diag;
-        a.RemoveDiag(a_no_diag);
-        idx_t* perm = new idx_t[a_no_diag.row_cnt_];
-        idx_t* iperm = new idx_t[a_no_diag.row_cnt_];
-        idx_t options[METIS_NOPTIONS];
-        METIS_SetDefaultOptions(options);
-        options[METIS_OPTION_NUMBERING] = 0;
-        // int METIS_NodeND(idx_t *nvtxs, idx_t *xadj, idx_t *adjncy, idx_t *vwgt,
-        //   idx_t *options, idx_t *perm, idx_t *iperm);
-
-        int result = METIS_NodeND(
-            &a_no_diag.row_cnt_
-            , a_no_diag.i_a_
-            , a_no_diag.j_a_
-            , nullptr
-            , options
-            , perm
-            , iperm
-        );
-        REQUIRE(result == METIS_OK);
     }
-
-    // REQUIRE(ReorderMatrix(a_no_diag) == METIS_OK);
+    REQUIRE(ReorderMatrix(a));
 }
 
 TEST_CASE("Size 128") {