Full Binary Tree（sdut 2882)

Problem Description:

In computer science, a binary tree is a tree data structure in which each node has at most two children. Consider an infinite full binary tree (each node has two children except the leaf nodes) defined as follows. For a node labelled v its left child will be labelled 2 * v and its right child will be labelled 2 * v + 1. The root is labelled as 1.

 

You are given n queries of the form i, j. For each query, you have to print the length of the shortest path between node labelled i and node labelled j.

 Input

First line contains n(1 ≤ n ≤ 10^5), the number of queries. Each query consists of two space separated integers i and j(1 ≤ i, j ≤ 10^9) in one line.

Output

For each query, print the required answer in one line.

 

Sample Input

5
1 2
2 3
4 3
1024 2048
3214567 9998877
题解 只要找到公共节点即可，水题一个；

#include<stdio.h>
#include<string.h>
int main()
{
    long long int i,j,a,b,m,n,p;
    scanf("%lld",&p);
    for(int k=0;k<p;k++)
    {
        scanf("%lld%lld",&a,&b);
        m=a>b?a:b;
        n=a>b?b:a;
        long long int count1=0,count2=0;
        while(m!=n)
        {
            if(n>m)
                n/=2;
            if(m==n)
                break;
            if(m>n)
            m/=2;
        }//找到公共节点；
        while(a!=m)
        {
            a/=2;
            count1++;
        }
        while(b!=m)
        {
            b/=2;
            count1++;
        }//统计下每一节点到公共节点的距离
        printf("%lld\n",count1);

    }
    return 0;
}