Compilare: user.cpp: In function ‘int main()’: user.cpp:102:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(index(v[j].fs, v[j].sc) == 0 && j < v.size()) ^ user.cpp:107:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < v.size() && index(v[j].fs, v[j].sc) == i) ^ user.cpp: In function ‘char gchar()’: user.cpp:22:38: 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:81:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qxy.in", "r", stdin); ^ user.cpp:82:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qxy.out", "w", stdout); ^