Compilare: user.cpp: In function ‘void Add_To_Hash(int, int, int&)’: user.cpp:21:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<h[x1].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:69:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("substr.in","r",stdin); ^ user.cpp:70:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("substr.out","w",stdout); ^ user.cpp:72:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d ",&N,&X); ^ user.cpp:73:11: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ user.cpp: In function ‘int Binary_Search(int)’: user.cpp:65:9: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ /tmp/ccWeg5zj.o: In function `main': user.cpp:(.text.startup+0x72): warning: the `gets' function is dangerous and should not be used.