{"trustable":false,"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":"现有序列a1, a2, ..., an。需要从中任意选出2*k个数,然后将这2*k个数两两配对。x和y配对的代价是(x-y)^2,比如2和5配对的代价就是9。求最终这k个数对的代价和的最小值。"}},{"title":"Input","value":{"format":"HTML","content":"有多个测试用例。请处理到EOF。\n每组数据有两行,第一行有两个数n,k(2\u0026lt;\u003d2*k\u0026lt;\u003dn\u0026lt;2000).第二行有n个整数表示ai(ai是一个小于2^15的正整数)."}},{"title":"Output","value":{"format":"HTML","content":"输出k个数对的代价和的最小值。"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre\u003e2 1\n1 3\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre\u003e4\u003c/pre\u003e"}}]}