Compilare: user.cpp: In function ‘int main()’: user.cpp:150:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[c].size() * v[c].size() <= n) ^ user.cpp:152:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[c].size(); i++) ^ user.cpp:153:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = i + 1; j < v[c].size(); j++) ^ user.cpp: In function ‘char gchar()’: user.cpp:18:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, buffer, 1, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:114:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kdist.in", "r", stdin); ^ user.cpp:115:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kdist.out", "w", stdout); ^