Compilare: user.cpp: In function ‘int main()’: user.cpp:58:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<strlen(s1);i++) ^ user.cpp:61:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<strlen(s1);i++) ^ user.cpp:64:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=(i+1);j<strlen(s1);j++) ^ user.cpp:10:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("cifre5.in","r",stdin); ^ user.cpp:11:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("cifre5.out","w",stdout); ^ user.cpp:12:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &v); ^ user.cpp:25:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%llu", &x); ^ user.cpp:56:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s1); ^ /tmp/ccTbj2t6.o: In function `main': user.cpp:(.text.startup+0x144): warning: the `gets' function is dangerous and should not be used.