我正在try 在C(就地)中转置一个(非正方形)矩阵.
****mats是指向动态分配的3D数组的指针
**ll是指向动态分配数组的指针，我在该数组中保存每个矩阵的行数
**lc是指向动态分配数组的指针，我在该数组中保存每个矩阵的列数
253 void transpose_mat(int ****mats, int **ll, int **lc, int k) {
254 int max_dim = (*lc)[k];
255 if ((*ll)[k] >= (*lc)[k])
256 max_dim = (*ll)[k];
257
258 (*mats)[k] = realloc((*mats)[k], max_dim * sizeof(***mats));
259 for (int i = 0; i < max_dim; ++i)
260 (*mats)[k][i] = realloc((*mats)[k][i], max_dim * sizeof(****mats));
261
262 for (int i = 0; i < max_dim; ++i) {
263 for (int j = i + 1; j < max_dim; ++j) {
264 int tmp = (*mats)[k][i][j];
265 (*mats)[k][i][j] = (*mats)[k][j][i];
266 (*mats)[k][j][i] = tmp;
267 }
268 }
269
270 int tmp = (*lc)[k];
271 (*lc)[k] = (*ll)[k];
272 (*ll)[k] = tmp;
273
274 (*mats)[k] = realloc((*mats)[k], (*ll)[k] * sizeof(***mats));
275 for (int i = 0; i < (*ll)[k]; ++i) {
276 (*mats)[k][i] = realloc((*mats)[k][i], (*lc)[k] * sizeof(****mats));
277 }
278}
Valgrindyields
1 2
1 2
----transpose_mat
==18654== Conditional jump or move depends on uninitialised value(s)
==18654== at 0x484DC80: realloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==18654== by 0x10A67A: transpose_mat (my_octave.c:260)
==18654== by 0x10B1CC: main (my_octave.c:436)
==18654== Uninitialised value was created by a heap allocation
==18654== at 0x484DCD3: realloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==18654== by 0x10A60C: transpose_mat (my_octave.c:258)
==18654== by 0x10B1CC: main (my_octave.c:436)
==18654==
2 1
1
2
---- free_k_matrix
==18654==
==18654== HEAP SUMMARY:
==18654== in use at exit: 0 bytes in 0 blocks
==18654== total heap usage: 14 allocs, 14 frees, 5,212 bytes allocated
==18654==
==18654== All heap blocks were freed -- no leaks are possible
==18654==
==18654== For lists of detected and suppressed errors, rerun with: -s
==18654== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
我错过了什么吗？
我try 初始化后，我重新锁定内存垫的价值观，但我最终与更多的错误和分段故障.