题解 | #二叉树#

#include <iostream>

using namespace std;

int CountNodes(int m, int n) {
    if (m > n) {
        return 0;
    }
    else {
        return CountNodes(2 * m, n) + CountNodes(2 * m + 1, n) + 1;
    }
}

int main()
{
    int m, n;
    while (cin >> m >> n) {
        if (m == 0 && n == 0) {
            break;
        }
        cout << CountNodes(m, n) << endl;
    }
    return 0;
}