Compilare: main.cpp:9:27: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] char line[MAX_N] = { NULL }; ^ main.cpp: In function 'int main()': main.cpp:18:33: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &n, &m); ^ main.cpp:31:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%s", line); ^