Compilare: main.cpp: In function 'void backtracking(long long int)': main.cpp:41:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (k == divisors.size()) { ~~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:85:27: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::map<long long int, long long int>::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n", mp.size()); ^ main.cpp:73:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("armonica.in", "r", stdin); ^ main.cpp:74:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("armonica.out", "w", stdout); ^ main.cpp:78:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &b); ^