Compilare: main.cpp: In function 'void print()': main.cpp:68:35: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf(g, "2 %d\n", op.size()); ^ main.cpp: In function 'void read()': main.cpp:25:24: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^ main.cpp:28:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &x); ^