Compilare: main.cpp: In function 'int main()': main.cpp:41:30: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<ABC>::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n", sol.size()); ^ main.cpp:43:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++) { ~~^~~~~~~~~~~~ main.cpp:31:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbsat2.in", "r", stdin); ^ main.cpp:32:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbsat2.out", "w", stdout); ^ main.cpp:33:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:36:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^