如题。

#include "bits/stdc++.h"
using namespace std;

int f[70000000];

int main() {
	int x, y, mx = -0x7fffffff, mn = 0x7fffffff;
	scanf ("%d%d", &x, &y);
	//freopen ("oeis.txt", "w", stdout);
	f[1] = 1;
	for (int i = 2; i <= y; ++i) {
		int j = i, cnt = 1;
		while (j > 30000005 || !f[j]) {
			if (j % 2) j = j * 3 + 1;
			else j = j / 2;
			if (j > 30000005 || !f[j]) ++cnt;
			else cnt += f[j];
		}
		f[i] = cnt;
		//cout << f[i] << ' ';
	}
	for (int i = x; i <= y; ++i) mx = max(mx, f[i]), mn = min(mn, f[i]);
	cout << mn << ' ' << mx << endl;
}