代码

#include <cstddef> // for size_t
#include <algorithm> // for std::swap

void partition(unsigned *a, size_t start, size_t length, int bit) {
    size_t left = start;
    size_t right = start + length - 1;
    while (left <= right) {
        if (((a[left] >> bit) & 1) == 0) {
            left++;
        } else {
            std::swap(a[left], a[right]);
            right--;
        }
    }
}

void sort(unsigned *a, size_t n) {
    for (int bit = 0; bit < 32; bit++) {
        partition(a, 0, n, bit);
    }
}

评测结果