Compilare: main.cpp: In function 'int main()': main.cpp:120:36: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::vector<int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf(out, "%d\n", sol.size()); ^ main.cpp:100:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &n, &m); ^ main.cpp:104:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &x, &y); ^