Compilare: user.cpp: In function ‘int main()’: user.cpp:2:394: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] char s[100021];int x;int e();int f(){int n,R,S,o,T;o=T=R=S=1;while(T){S=1;n=0;if(s[x]=='-')S=-S,++x;else if(s[x]=='+')++x;if(s[x]=='(')x++,n=e();else for(;'0'<=s[x]&&s[x]<='9';n=n*10+s[x++]-48);if(o)R*=S*n;else if(n)R/=n;else R=0;if(s[x]=='/')o=0,x++;else if(s[x]=='*')o=1,x++;else T=0;}return R;}int e(){int S=0;while(s[x]!=')')S+=f();++x;return S;}int main(){freopen("evaluare.in","r",stdin);freopen("evaluare.out","w",stdout);scanf("%s",s);printf("%d", e() );} ^ user.cpp:2:429: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] char s[100021];int x;int e();int f(){int n,R,S,o,T;o=T=R=S=1;while(T){S=1;n=0;if(s[x]=='-')S=-S,++x;else if(s[x]=='+')++x;if(s[x]=='(')x++,n=e();else for(;'0'<=s[x]&&s[x]<='9';n=n*10+s[x++]-48);if(o)R*=S*n;else if(n)R/=n;else R=0;if(s[x]=='/')o=0,x++;else if(s[x]=='*')o=1,x++;else T=0;}return R;}int e(){int S=0;while(s[x]!=')')S+=f();++x;return S;}int main(){freopen("evaluare.in","r",stdin);freopen("evaluare.out","w",stdout);scanf("%s",s);printf("%d", e() );} ^ user.cpp:2:443: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] char s[100021];int x;int e();int f(){int n,R,S,o,T;o=T=R=S=1;while(T){S=1;n=0;if(s[x]=='-')S=-S,++x;else if(s[x]=='+')++x;if(s[x]=='(')x++,n=e();else for(;'0'<=s[x]&&s[x]<='9';n=n*10+s[x++]-48);if(o)R*=S*n;else if(n)R/=n;else R=0;if(s[x]=='/')o=0,x++;else if(s[x]=='*')o=1,x++;else T=0;}return R;}int e(){int S=0;while(s[x]!=')')S+=f();++x;return S;}int main(){freopen("evaluare.in","r",stdin);freopen("evaluare.out","w",stdout);scanf("%s",s);printf("%d", e() );} ^