Compilare: user.cpp:34:0: warning: "maxN" redefined [enabled by default] #define maxN 2016 ^ user.cpp:17:0: note: this is the location of the previous definition #define maxN 90111 ^ user.cpp: In function ‘void add_solution(int, int, int)’: user.cpp:180:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < act.size(); i++) { ^ user.cpp:249:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < act.size(); i++) ^ user.cpp:175:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, target; ^ user.cpp:175:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, target; ^ user.cpp: In function ‘int main()’: user.cpp:307:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i + 2 < way.size(); i += 2) ^ user.cpp:258:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("santa.out","w",stdout); ^ user.cpp: In member function ‘void Buffer::refill()’: user.cpp:70:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&data[0], 1, dim, stdin); ^ user.cpp: In constructor ‘Buffer::Buffer(std::string, int)’: user.cpp:39:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(name.c_str(), "r", stdin); ^