[c++ IO加速]快速输入输出

自己封装的FastIO类，效率虽有所损失，不过实用性提高很多。

测试，写10000000个整数(86M)：

• printf 2.7s
• cout 27s
• FastIO 1s

测试，读10000000个整数(86M)：

• scanf 1.8s
• cin 15s
• FastIO 1s

 　　　　　　

利用c++的可变参数模板(c++11)和重载可以轻松实现数量不定的混合输入输出。

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class FastIO { public: FastIO() { pin = in; countin = countout = ; } int read2mem() { return countin = fread(in, , insize, stdin); fclose(stdin); } int write2disk() { return fwrite(out, , countout, stdout); fclose(stdout); } int read() { return ; } template<typename T, typename ...R> int read(T &f, R &...r) { if (get(f) == -) return -; c = read(r...); if (c == -) return -; return + c; } void write() { put('\n'); } template<typename T, typename ...R> void write(const T x, const R ...r) { put(x); write(r...); } private: const static int insize = ( << ) * , outsize = ( << ) * ; char in[insize], out[outsize], *pin; int countin, countout, a[], c, negative;   /*** read ***/ inline bool digit(const char ch) { return ch == '-' || ch >= '0' && ch <= '9'; } int get(char s[]) { while ((*pin == ' ' || *pin == '\n') && pin - in != countin) pin ++; if (pin - in == countin) return -; while (*pin != ' ' && *pin != '\n' && pin - in != countin) *s ++ = *pin ++; *s = ; return ; } int get(char &ch) { if (pin - in == countin) return -; ch = *pin ++; return ; } int get(int &buf) { while (!digit(*pin) && pin - in != countin) pin ++; if (pin - in == countin) return -; buf = ; negative = ; if (*pin == '-') { negative = ; pin ++; } while (digit(*pin) && pin - in != countin) { buf = buf * + *pin - '0'; pin ++; } if (negative) buf = -buf; return ; } /*** write ***/ void put(unsigned int x) { c = ; a[c ++] = x % + '0'; x /= ; while (x) { a[c ++] = x % + '0'; x /= ; } while (c) { out[countout ++] = a[-- c]; } } void put(int x) { c = ; negative = x < ; if (negative) { x = -x; out[countout ++] = '-'; } a[c ++] = x % + '0'; x /= ; while (x) { a[c ++] = x % + '0'; x /= ; } while (c) { out[countout ++] = a[-- c]; } } void put(const char &ch) { out[countout ++] = ch; } void put(char s[]) { while (*s) out[countout ++] = *s ++; } };