Compilare: user.cpp: In function ‘int main()’: user.cpp:52:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < Sol[i].size(); ++j) { ^ user.cpp:22:38: 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:24:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a + 1); ^ /tmp/ccR3cN5H.o: In function `main': user.cpp:(.text.startup+0x67): warning: the `gets' function is dangerous and should not be used.