uvalive 4727 jump跳跃（dp/约瑟夫问题变形）



题意是： 个数组成一个环，从第k个元素开始删除，每隔k个元素删一个，问最后删除的三个是什么

思路：约瑟夫问题变形，倒数第二个第三个求法与最后一个元素求法相同

#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#include<vector>
#include<map>
#include<queue>
#include<stack>
#include<string>
#include<map>
#include<set>
#define eps 1e-6
#define LL long long
using namespace std;  

const int maxn = 500000 + 100;
const int INF = 0x3f3f3f3f;
//freopen("input.txt", "r", stdin);
int f1[maxn], f2[maxn], f3[maxn], n, k;

void cal_f() {
	f3[3] = (k-1) % 3;
    f2[3] = (k%2 == 0 ? (2+f3[3])%3 : (1+f3[3])%3);
	f1[3] = 3 - f2[3] - f3[3];
	for(int i = 4; i <= n; i++) {
		f1[i] = (f1[i-1]+k) % i;
		f2[i] = (f2[i-1]+k) % i;
		f3[i] = (f3[i-1]+k) % i;
	}
	f1[n]++; f2[n]++; f3[n]++;
}

int main() {
	int t; scanf("%d", &t);
	while(t--) {
		scanf("%d%d", &n, &k);
		cal_f();
		//for(int i = 3; i <= n; i++) printf("%d %d %d\n", f3[i], f2[i], f1[i]);
		printf("%d %d %d\n", f3[n], f2[n], f1[n]);
	}
	return 0;
}