Compilare: user.cpp: In function ‘int main()’: user.cpp:17:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < strlen(S); i++) ^ user.cpp:16:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S); ^ user.cpp:28:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:31:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &X); ^ /tmp/ccmNsV6Z.o: In function `main': user.cpp:(.text.startup+0x1d): warning: the `gets' function is dangerous and should not be used.