Compilare: user.cpp: In function ‘int main()’: user.cpp:27:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=1;j<=strlen(s+1);j++){ ^ user.cpp:31:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<in.size();j++) ^ user.cpp:20:26: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("1.in","r",stdin); ^ user.cpp:21:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("1.out","w",stdout); ^ user.cpp:22:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&t); ^ user.cpp:24:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&n,&k); ^ user.cpp:25:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s+1); soll=0; in.clear(); ^ /tmp/ccW9vivj.o: In function `main': user.cpp:(.text.startup+0xa4): warning: the `gets' function is dangerous and should not be used.