代码

#include <stdio.h>
#include <string.h>

void sort(unsigned * a, int n) {
	int cnt[256];
	static unsigned _b[100000005];
	unsigned *b = _b;
	for (int i = 0; i < 32; i += 8) {
		memset(cnt, 0, sizeof(int) * 256);
		for (int j = 0; j < n; ++ j) cnt[a[j] >> i & 255] ++;
		for (int j = 1; j < 256; ++ j) cnt[j] += cnt[j - 1];
		for (int j = n - 1; ~j; -- j) b[-- cnt[a[j] >> i & 255]] = a[j];
		unsigned * tmp = a; a = b; b = tmp;
	}
}

评测结果