代码

#define O3 __attribute__((optimize("-Ofast")))

#include <cstdio>
#include <algorithm>

int d[11];

// lexicographical_order: 64.865 ms / 421.017 ms
extern void lexicographical_order(const int size) O3;
void lexicographical_order(const int size)
{
    int tot = 1, i, *pi, *pj, *pk, *pe = d+size-1;
    for (i = 0; i < size; i++) d[i] = i+1, tot *= i+1;
    // for (pi = d; pi != pe; pi++) printf("%d ", *pi); printf("%d\n", *pe);
    while (--tot)
    {
        pi = d + (size - 2);
        while (*pi > *(pi+1)) pi--;
        pj = pi + 1;
        pk = d + (size - 1);
        while (pj < pk) {
            std::swap(*pj, *pk);
            pj++; pk--;
        }
        pj = d + (size - 2);
        while (*pj > *pi) pj--;
        std::swap(*pi, *(pj+1));
        // for (pi = d; pi != pe; pi++) printf("%d ", *pi); printf("%d\n", *pe);
    }
}

int main()
{
    // lexicographical_order(5);
    // lexicographical_order(9);
    lexicographical_order(11);
    return 0;
} 

评测结果