各种读入方式速度比较

1 inline void read(int &n)
2 {
3     char c=getchar();bool flag=0;n=0;
4     while(c<'0'||c>'9')    c=='-'?flag=1,c=getchar():c=getchar();
5     while(c>='0'&&c<='9')    n=n*10+c-48,c=getchar();flag==1?n=-n:n=n;
6 }

1 inline void read(int &x)
2 {
3     char ch=getchar();x=0;int f=1;
4     for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-1;
5     for(;isdigit(ch);ch=getchar())x=x*10+ch-'0';x=x*f;
6 }

1 inline int read()
2 {
3     int x=0,f=1;char c=getchar();
4     while(c<'0'||c>'9')    {if(c=='-')    f=-1;c=getchar();}
5     while(c>='0'&&c<='9')    x=x*10+c-48,c=getchar();    return x*f;
6 }

 1 inline char nc(){
 2     static char buf[100000],*p1=buf,*p2=buf;
 3     return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
 4 }
 5 inline int read()
 6 {
 7     char ch=nc();int sum=0;int flag=1;
 8     while(!(ch>='0'&&ch<='9')){ch=nc();if(ch=='-')flag=-1;}
 9     while(ch>='0'&&ch<='9')sum=sum*10+ch-48,ch=nc();
10     return sum*flag;
11 }