Compilare: main.cpp: In function 'int main()': main.cpp:45:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("ace.in", "r", stdin); ^ main.cpp:46:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("ace.out", "w", stdout); ^ main.cpp:47:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &p); ^ main.cpp:48:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &m); ^ main.cpp:51:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &mat[i][j]); ^