Compilare: user.cpp:2:53: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] int x,p,s[1<<22];std::string c,a,b="strmatch.";main(){std::ofstream g(b+"out");for(std::ifstream(b+"in")>>a>>b;p=b.find(a,p)+1;s[x++]=p-1);for(g<<x<<c;p<x&p<1000;g<<s[p++]<<' ');} ^ user.cpp: In function ‘int main()’: user.cpp:2:126: warning: suggest parentheses around assignment used as truth value [-Wparentheses] int x,p,s[1<<22];std::string c,a,b="strmatch.";main(){std::ofstream g(b+"out");for(std::ifstream(b+"in")>>a>>b;p=b.find(a,p)+1;s[x++]=p-1);for(g<<x<<c;p<x&p<1000;g<<s[p++]<<' ');} ^ user.cpp:2:153: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] int x,p,s[1<<22];std::string c,a,b="strmatch.";main(){std::ofstream g(b+"out");for(std::ifstream(b+"in")>>a>>b;p=b.find(a,p)+1;s[x++]=p-1);for(g<<x<<c;p<x&p<1000;g<<s[p++]<<' ');} ~^~