快读快写

超极快读快写

#include <bits/stdc++.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdint.h> 
#include <ctype.h>  
#include <cstring> 
using namespace std;
constexpr size_t MSIZE = 1 << 25;    
constexpr size_t PRE_DATA_SIZE = 0x10000;
const int PROT = PROT_READ;    
const int FLAGS = MAP_PRIVATE;    
char* c = nullptr;
uint64_t pre_data[PRE_DATA_SIZE]; 
using u32 = uint64_t;
inline void init_pre_data() {
    fill_n(pre_data, PRE_DATA_SIZE, UINT32_MAX);
    for (size_t i = 0; i < 10; ++i) {
        for (size_t j = 0; j < 10; ++j) {
            uint16_t key = (('0' + j) << 8) | ('0' + i);
            pre_data[key] = i + j * 10;
        }
    }
}

inline u32 readu() {
    while (*c <= ' ') ++c;
    
    u32 x = 0;
    while (true) {
        uint16_t key;
        memcpy(&key, c, sizeof(key));
        if (pre_data[key] != UINT32_MAX) {
            x = x * 100 + pre_data[key];
            c += 2; 
        } else {
            break;
        }
    }
    if (isdigit(static_cast<unsigned char>(*c))) {
        x = x * 10 + (*c - '0');
        ++c;
    }
    return x;
}

inline void write_str(const char* s) {
    while (*s != '\0') {
        putchar_unlocked(*s);
        ++s;
    }
}

inline void write_u32(u32 x) {
    static char buf[12]; 
    char* ptr = buf + 11;
    *ptr = '\0'; 
    
    if (x == 0) {
        *(--ptr) = '0'; 
    } else {
        while (x > 0) {
            *(--ptr) = (x % 10) + '0';
            x /= 10;
        }
    }
    write_str(ptr);
    putchar_unlocked('\n'); 
}
inline void cleanup() {
    if (c != MAP_FAILED && c != nullptr) {
        munmap(c, MSIZE);
    }
}

int main() {
    int fd = open("/dev/stdin", O_RDONLY);
    if (fd == -1) {
        perror("open stdin failed");
        exit(EXIT_FAILURE);
    }
    c = static_cast<char*>(mmap( nullptr, MSIZE, PROT,FLAGS, fd, 0));
    close(fd); 
    if (c == MAP_FAILED) {
        perror("mmap failed");
        exit(EXIT_FAILURE);
    }
    atexit(cleanup);
    init_pre_data();
    u32 k = readu();
    while (k >= 4) {
        write_u32(readu() ^ readu());
        write_u32(readu() ^ readu());
        write_u32(readu() ^ readu());
        write_u32(readu() ^ readu());
        k -= 4;
    }
    while (k-- > 0) {
        write_u32(readu() ^ readu());
    }
    return 0;
}