读入优化

• fread 读入

有莫名其妙的问题，一般不用

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

• getc(stdio) 读入

用的最多

inline void read(int &x)
{
    x = 0;int f = 1;char ch;
    ch = getc(stdin);
    while(ch > '9'||ch < '0') {if(ch == '-') f = -1;ch = getc(stdin);}
    while(ch <= '9'&&ch >= '0') {x = (x * 10) + (ch ^ 48);ch = getc(stdin);}
    x *= f;
}