Compilare: user.cpp: In function ‘int main()’: user.cpp:162:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < V.size(); ) ^ user.cpp:165:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < V.size() && V[i].Hash1 == V[j].Hash1 && V[i].Hash2 == V[j].Hash2) j ++; ^ user.cpp:95:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pal2.in", "r", stdin); ^ user.cpp:96:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pal2.out", "w", stdout); ^ user.cpp:98:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(A + 1); M = strlen(A + 1); ^ /tmp/ccJK6gPa.o: In function `main': user.cpp:(.text.startup+0x61): warning: the `gets' function is dangerous and should not be used.