Compilare: main.cpp: In function 'int main()': main.cpp:46:43: warning: format '%d' expects argument of type 'int', but argument 4 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] fprintf(out, "%d %d\n", ans, oo.size()) ; ^ main.cpp:27:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d\n", &n) ; ^ main.cpp:30:39: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d\n", &x, &y) ; ^