{"trustable":false,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\n\u003cscript\u003e\n window.katexOptions \u003d {\n delimiters: [\n {left: \u0027$$$$$$\u0027, right: \u0027$$$$$$\u0027, display: true},\n {left: \u0027$$$\u0027, right: \u0027$$$\u0027, display: false},\n {left: \u0027$$\u0027, right: \u0027$$\u0027, display: true},\n {left: \u0027$\u0027, right: \u0027$\u0027, display: false}\n ]\n };\n\u003c/script\u003e\n","sections":[{"title":"","value":{"format":"MD","content":"给定一个长度为$n$的数组$a$和一个整数$k$,构造数组$d_i \u003d |a_i - x|$并升序排序,求最优的$x$值使得排序后的$d_{k+1}$尽量小。"}},{"title":"Input","value":{"format":"MD","content":"第一行包含一个整数$T$,表示数据组数\n对于没租数据,第一行两个整数$n, k$,其中$1 \\leq n \\leq 2 \\cdot 10^5, 0 \\leq k \u003c n$;\n第二行$n$个整数表示数组$a$,其中$1 \\leq a_i \\leq 10^9$。\n保证所有数据中的n的和不超过$2 \\cdot 10^5$"}},{"title":"Output","value":{"format":"MD","content":"输出共$T$行,每行一个整数$x$表示答案。"}},{"title":"Example","value":{"format":"MD","content":"\u003cdiv class\u003d\"sample-test\"\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e3\n3 2\n1 2 5\n2 1\n1 1000000000\n1 0\n4\n\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003e3\n500000000\n4\n\u003c/pre\u003e\n \u003c/div\u003e\n\u003c/div\u003e"}}]}