Compilare: user.cpp: In function ‘long long int calc(int, int)’: user.cpp:55:13: warning: unused variable ‘st’ [-Wunused-variable] int i,j,st,dr,nr=0,q2; ^ user.cpp:55:16: warning: unused variable ‘dr’ [-Wunused-variable] int i,j,st,dr,nr=0,q2; ^ user.cpp: In function ‘int main()’: user.cpp:133:13: warning: unused variable ‘j’ [-Wunused-variable] int n,i,j,m,op,x,y,z; ^ user.cpp:131:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("diez.in","r",stdin); ^ user.cpp:132:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("diez.out","w",stdout); ^ user.cpp:142:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&n,&m); ^ user.cpp:144:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(si+1); ^ user.cpp:151:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&op); ^ user.cpp:154:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %c",&x,&ch); ^ user.cpp:159:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&z); ^ /tmp/ccO8A5FU.o: In function `main': user.cpp:(.text.startup+0x10d): warning: the `gets' function is dangerous and should not be used.