KazaQ's Socks HDU - 6043

KazaQ wears socks everyday. At the beginning, he has nn pairsof socks numbered from 11 to nn inhis closets. Every morning, he puts on a pair of socks which has the smallest number in the closets. Every evening, he puts this pair of socks in the basket. If there are n−1n−1 pairsof socks in the basket now, lazy KazaQ has to wash them. These socks will be put in the closets again in tomorrow evening. KazaQ would like to know which pair of socks he should wear on the kk-thday.InputThe input consists of multiple test cases. (about 20002000) For each case, there is a line contains two numbers n,kn,k (2≤n≤109,1≤k≤1018)(2≤n≤109,1≤k≤1018).OutputFor each test case, output " Case #xx: yy"in one line (without quotes), where xx indicatesthe case number starting from 11 and yydenotesthe answer of corresponding case.Sample Input

3 7
3 6
4 9

Sample Output

Case #1: 3
Case #2: 1
Case #3: 2

找规律  模拟

#include <stdio.h>typedef long long ll;int main() {ll n , k , m , m1 , m2;int Case = 1;while(~scanf("%lld%lld",&n,&k)) {if(k <= n) m = k;else {m = k - n;m1 = m/(n-1);m2 = m%(n-1);if(m2) {if(m1%2) {m = m2;}else{if(m2 == n-1) m = n;else m = m2;}}else {if(m1%2) m = n-1;else m = n;}}printf("Case #%d: %d\n",Case++,m);}return 0;}