放在 using namespace std; 后面即可。
namespace fast_IO {
#define FASTIO
#define IOSIZE 100000char ibuf[IOSIZE], obuf[IOSIZE];char *p1 = ibuf, *p2 = ibuf, *p3 = obuf;
#ifdef ONLINE_JUDGE
#define getchar() ((p1==p2)and(p2=(p1=ibuf)+fread(ibuf,1,IOSIZE,stdin),p1==p2)?(EOF):(*p1++))
#define putchar(x) ((p3==obuf+IOSIZE)&&(fwrite(obuf,p3-obuf,1,stdout),p3=obuf),*p3++=x)
#endif//fread in OJ, stdio in local#define isdigit(ch) (ch>47&&ch<58)
#define isspace(ch) (ch<33)template<typename T> inline T read() {T s = 0;int w = 1;char ch;while (ch = getchar(), !isdigit(ch) and (ch != EOF)) if (ch == '-') w = -1;if (ch == EOF) return false;while (isdigit(ch)) s = s * 10 + ch - 48, ch = getchar();return s * w;}template<typename T> inline bool read(T &s) {s = 0;int w = 1;char ch;while (ch = getchar(), !isdigit(ch) and (ch != EOF)) if (ch == '-') w = -1;if (ch == EOF) return false;while (isdigit(ch)) s = s * 10 + ch - 48, ch = getchar();return s *= w, true;}inline bool read(char &s) {while (s = getchar(), isspace(s));return true;}inline bool read(char *s) {char ch;while (ch = getchar(), isspace(ch));if (ch == EOF) return false;while (!isspace(ch)) *s++ = ch, ch = getchar();*s = '\000';return true;}template<typename T> inline void print(T x) {if (x < 0) putchar('-'), x = -x;if (x > 9) print(x / 10);putchar(x % 10 + 48);}inline void print(char x) {putchar(x);}inline void print(char *x) {while (*x) putchar(*x++);}inline void print(const char *x) {for (int i = 0; x[i]; ++i) putchar(x[i]);}inline bool read(std::string& s) {s = "";char ch;while (ch = getchar(), isspace(ch));if (ch == EOF) return false;while (!isspace(ch)) s += ch, ch = getchar();return true;}inline void print(std::string x) {for (int i = 0, n = x.size(); i < n; ++i)putchar(x[i]);}template<typename T, typename... T1> inline int read(T& a, T1&... other) {return read(a) + read(other...);}template<typename T, typename... T1> inline void print(T a, T1... other) {print(a);print(other...);}struct Fast_IO {~Fast_IO() {fwrite(obuf, p3 - obuf, 1, stdout);}} io;template<typename T> Fast_IO& operator >> (Fast_IO &io, T &b) {return read(b), io;}template<typename T> Fast_IO& operator << (Fast_IO &io, T b) {return print(b), io;}
#define cout io
#define cin io
#define endl '\n'
}
using namespace fast_IO;