HDU 4952Number Transformation（找规律）

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=4952

Number Transformation

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 223 Accepted Submission(s): 98

Problem Description

Teacher Mai has an integer x.

He does the following operations k times. In the i-th operation, x becomes the least integer no less than x, which is the multiple of i.

He wants to know what is the number x now.

Input

There are multiple test cases, terminated by a line "0 0".

For each test case, the only one line contains two integers x,k(1<=x<=10^10, 1<=k<=10^10).

Output

For each test case, output one line "Case #k: x", where k is the case number counting from 1.

Sample Input

2520 102520 200 0

Sample Output

Case #1: 2520Case #2: 2600

AC代码：

#include<stdio.h>__int64 x,k,i,p,t;int main(){t=1;while(~scanf("%I64d%I64d",&x,&k)&&x+k){p=x;for(i=2;i<=k;i++){p=p-p/i;if(p<i)break;}printf("Case #%I64d: %I64d\n",t++,p*k);}return 0;}