{"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\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 type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"题目","value":{"format":"HTML","content":"我好想写dfs啊,但是教练说,bfs学会了才能学dfs。\u003cbr\u003e\n现在教练给你一棵树,你给出了这颗树的bfs序,现在你能帮助教练判断这个bfs序是正确的吗?"}},{"title":"输入","value":{"format":"HTML","content":"第一行一个整数n(n\u003c\u003d200000),代表树的节点数。\u003cbr\u003e\n接下来n-1行,每行两个数字u、v,代表u和v之间有一条边。\u003c\\br\u003e\n接下来一行,n个整数,代表bfs序。"}},{"title":"输出","value":{"format":"HTML","content":"如果bfs序正确,则输出Yes,否则输出No。\u003cbr\u003e\n注意,这是有根树,树根为1号节点。"}},{"title":"样例输入1","value":{"format":"HTML","content":"4\u003cbr\u003e\n1 2\u003cbr\u003e\n1 3\u003cbr\u003e\n1 4\u003cbr\u003e\n1 4 3 2"}},{"title":"样例输出1","value":{"format":"HTML","content":"Yes"}},{"title":"样例输入2","value":{"format":"HTML","content":"4\u003cbr\u003e\n1 2\u003cbr\u003e\n1 3\u003cbr\u003e\n1 4\u003cbr\u003e\n4 2 3 1"}},{"title":"样例输出2","value":{"format":"HTML","content":"No"}},{"title":"样例输入3","value":{"format":"HTML","content":"4\u003cbr\u003e\n1 2\u003cbr\u003e\n1 3\u003cbr\u003e\n1 4\u003cbr\u003e\n1 2 4 3"}},{"title":"样例输出3","value":{"format":"HTML","content":"Yes"}},{"title":"样例输入4","value":{"format":"HTML","content":"4\u003cbr\u003e\n1 2\u003cbr\u003e\n1 3\u003cbr\u003e\n2 4\u003cbr\u003e\n1 2 4 3"}},{"title":"样例输入4","value":{"format":"HTML","content":"No"}}]}