{"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\"\u003e给定一个字符串 $S$。$S$ 仅包含小写英文字母。$(10 \\leq length(S) \\leq 1,000,000)$\u003cbr\u003e有多少子串包含至少 $k(1 \\leq k \\leq 26)$ 个不同的字符?\u003c/div\u003e"}},{"title":"输入","value":{"format":"HTML","content":"有多个测试用例。第一行包含一个整数 $T (1\\leq T\\leq 10)$,表示测试用例的数量。对于每个测试用例:\u003cbr\u003e\u003cbr\u003e第一行包含字符串 $S$。\u003cbr\u003e第二行包含一个整数 $k(1 \\leq k \\leq 26)$。"}},{"title":"输出","value":{"format":"HTML","content":"对于每个测试用例,输出包含至少 $k$ 个不同字符的子串数量。"}},{"title":"示例","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\u003e2\r\nabcabcabca\r\n4\r\nabcabcabcabc\r\n3\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e0\r\n55\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}}]}