Problem 2147 A-B Game (math AH)

Title Link: http://acm.fzu.edu.cn/problem.php?pid=2147

Problem Description

Fat brother and Maze is playing a kind of special (hentai) game by, integers a and B. First Fat brother write an integer A in a white paper and then Maze start to change this integer. Every time Maze can select an integer x between 1 and A-1 then change A to A A-(a%x). The game ends when this integer is less than or equals to B. Here are the problem, at least-many times Maze needs to perform to-end this special (hentai) game.

Input

The first line of the date is a integer T, which is the number of the text cases.

Then T cases follow, each case contains the integers A and B described above.

1 <= T <=100, 2 <= B < A < 100861008610086

Output

For each case, output the case number first, and then output a integer describes the number of times Maze needs to perfor M. See the sample, input and output for more details.

Sample Input25 310086 outputcase 1:1case 2:7

Test instructions

Give the number a of two long integers, b. There is an action that changes a to: a=a-(a%x), where 1<=x<=a-1;

Ask at least how many times the operation can make a<=b.

The code is as follows:

#include <cstdio> #define LL __int64int Main () {    int cas=1;    LL t,a,b;    scanf ("%i64d", &t);    while (t--)    {        scanf ("%i64d%i64d", &a,&b);        LL i=0;        while (a>b)        {            a/=2;            i++;        }        printf ("Case%d:", cas++);        printf ("%i64d\n", I);    }    return 0;}

Problem 2147 A-B Game (math AH)