C++ 빠른 콘솔 입출력 함수

 C++ 문자 입출력 함수 (*필수)

#include <iostream>
#include <cstring>
using namespace std;

const int BUF_SIZE = 1 << 20;    // 메모리 초과 가능, 적당히 조절할 것.
char input_buf[BUF_SIZE], output_buf[BUF_SIZE];
int input_buf_pos, output_buf_pos;
enum io_mode {READ, WRITE};


inline void char_io(io_mode mode, char &target)
{
        if(mode == READ) {
                if (input_buf_pos == BUF_SIZE)
                {
                        fread(input_buf, sizeof(char), BUF_SIZE, stdin);
                        input_buf_pos = 0;
                }
                target = input_buf[input_buf_pos++];
        }
        else {
                if(output_buf_pos == BUF_SIZE || target == EOF)
                {
                        fwrite(output_buf, sizeof(char), output_buf_pos, stdout);
                        output_buf_pos = 0;
                }
                output_buf[output_buf_pos++] = target;
        }
}
inline void char_io(io_mode mode, char &&target){
        char_io(mode, target);
}

usage :

char target;

char_io(READ, target);  // 입력버퍼 → target
char_io(WRITE, target);  // target → 출력버퍼
char_io(WRITE, EOF);  // 출력버퍼에 적힌 내용 flush.

 C++ 32비트 정수 입출력 함수  (선택)

inline void int_io(io_mode mode, int &target)
{
        char c;
        if(mode == READ){
                bool negative = false;
                int ret = 0;
                while(true)
                {
                        char_io(READ, c);
                        if(c == '\n' || c == ' ') break;
                        if(c == '-') {
                                negative = true;
                                continue;
                        }
                        ret = ret * 10 + (c & 0b1111);
                }
                target = negative ? -ret : ret;
        }
        else {
                int abs = target;
                int div = 1'000'000'000;
                char quotient = 0;
                if(abs < 0) {
                        char_io(WRITE, '-');
                        abs *= -1;
                }
                while(abs < div && div != 1) { div /= 10; }
                while(div != 0){
                        quotient = '0' + (char)((abs / div)%10);
                        char_io(WRITE, quotient);
                        div /= 10;
                }
        }
}
inline void int_io(io_mode mode, int &&target){
        int_io(mode, target);
}

usage :

int target;

int_io(READ, target);  
int_io(WRITE, target);
char_io(WRITE, EOF);  // 출력버퍼에 적힌 내용 flush.

 C++ 단어 입출력 함수  (선택)

inline void word_io(io_mode mode, char *&target){
        char c = 0;
        char* pos = target;
        if(mode == READ){
                while(c == 0) char_io(READ, c);
                while(true){
                        if(c == 0 || c == '\n' || c==' ') break;
                        *pos++ = c;
                        char_io(READ, c);
                }
        }
        else {
                while(true){
                        c = *(pos++);
                        if(c == 0 || c == '\n' || c ==' ') break;
                        char_io(WRITE, c);
                }
        }
}
inline void word_io(io_mode mode, char *&&target){
        word_io(mode, target);
}

usage :

char target[50];

word_io(READ, target);  
word_io(WRITE, target);
char_io(WRITE, EOF);  // 출력버퍼에 적힌 내용 flush.

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