为什么本地Linux机可以运行洛谷会RE?

inline int read()
{
    int x=0;char c=gc();
    while(!isdigit(c)) {c=gc();}
    while(isdigit(c)) {x=(x*10)+c-'0';c=gc();}
    return x;
}

xx[read()]=read();

int x=read(),p=read();
xx[x]=p;