{"trustable":true,"prependHtml":"\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003eGiven a permutation $p$ of $\\{1,2,\\cdots, n\\}$ and a non-negative integer $k$. Please calculate the number of subsets $T$ of $\\{1,2,3,4,...n\\}$ satisfying $|T|\u003dk$ and $|P(T)\\cap T|\u003d0$.\u003cbr\u003e\u003cbr\u003eWhere $P(T)$ means $P(T)\u003d\\lbrace y|y\u003dp_x,x\\in T\\rbrace$.\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"Each test contains multiple test cases. The first line contains the number of test cases $(1 \\le T \\le 15)$. Description of the test cases follows.\u003cbr\u003e\u003cbr\u003eThe first line contains two separated integers $n$, $k$.\u003cbr\u003e\u003cbr\u003eThe second line contains $n$ integers $P_1, P_2, \\cdots, P_n\\,(1\\le P_i \\le n)$, denoting the given permutation.\u003cbr\u003e\u003cbr\u003e$1\\leq n\\leq 5 \\times 10^5, 0\\leq k\\leq n$.\u003cbr\u003e\u003cbr\u003eFor all test cases,$\\sum n\\leq 5\\times 10^6$"}},{"title":"Output","value":{"format":"HTML","content":"For each test case:\u003cbr\u003e\u003cbr\u003ePrint one integer in a line, denoting the answer number modulo $998\\ 244\\ 353$."}},{"title":"Sample","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e3\r\n5 1\r\n5 3 2 1 4\r\n5 2\r\n2 5 1 3 4\r\n10 3\r\n10 9 3 8 6 4 5 7 2 1\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e5\r\n5\r\n40\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}