{"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":"\u003cscript type\u003d\u0027text/x-mathjax-config\u0027\u003eMathJax.Hub.Config({tex2jax: { inlineMath: [[\u0027$\u0027,\u0027$\u0027]] } }); \u003c/script\u003e\n\u003cscript type\u003d\u0027text/javascript\u0027 src\u003d\u0027https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\u0027\u003e\u003c/script\u003e\n\u003cscript type\u003d\u0027text/javascript\u0027\u003esetTimeout(function(){MathJax.Hub.Queue([\u0027Typeset\u0027, MathJax.Hub, \u0027left_view\u0027]);}, 2000);\u003c/script\u003e\n\u003cdiv class\u003d\"panel_content\"\u003e\n有n个数,对于这n个数,每次只能执行下面两种操作其中的一种:\u003cbr\u003e\n一:将相邻的两个数相加合并成一个数,\u003cbr\u003e\n二:将一个数分成相邻的两个数,这两个数的和仍然等于之前的数\u003cbr\u003e\n请问至少需要多少次操作才能将这n个数变成k个相等的数。\u003cbr\u003e\n\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\n第一行是一个数t,代表有t组样例。(1≤T≤100) \u003cbr\u003e\n每组样例的第一行是两个数n(1≤n≤10^5)和k(1≤k≤10^5) \u003cbr\u003e\n接下来一行是n个数a0,a1,a2......an-1"}},{"title":"Output","value":{"format":"HTML","content":"对于每组样例,输出的格式是 \u0027Case #x: y\u0027,x代表这是第几个case,从1开始,y是最少的操作次数,\u003cbr\u003e\n如果不能将这n个数变成相等的k个数,则y为-1."}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre\u003e3\n1 3\n14\n3 1\n2 3 4\n3 6\n1 2 3\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre\u003eCase #1: -1\nCase #2: 2\nCase #3: 3\u003c/pre\u003e"}}]}