Compilare: user.cpp: In function ‘int main()’: user.cpp:51:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < Sol[i].size(); ++j) { ^ user.cpp:23:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("litere2.in", "r", stdin); ^ user.cpp:25:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a); ^ /tmp/ccIC0bH5.o: In function `main': user.cpp:(.text.startup+0x6d): warning: the `gets' function is dangerous and should not be used.