Compilare: user.cpp: In function ‘int get_number(int&)’: user.cpp:12:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[p]>='0' && s[p]<='9' && p<strlen(s)) ^ user.cpp: In function ‘int main()’: user.cpp:107:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in","r",stdin); ^ user.cpp:108:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.out","w",stdout); ^ user.cpp:109:27: 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:112:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x[++x[0]]); ^ user.cpp:113:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^ user.cpp:121:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccZOkCx0.o: In function `main': user.cpp:(.text.startup+0x1e8): warning: the `gets' function is dangerous and should not be used.