{"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":"题目描述","value":{"format":"MD","content":"\u003cscript src\u003d\"https://cdn.bootcss.com/mathjax/2.7.0/MathJax.js\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e\n\u003cscript src\u003d\"https://cdn.bootcss.com/mathjax/2.7.0/config/TeX-AMS-MML_SVG.js\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e\n\n你需要模拟一个整数数列编辑器。编辑器初始时,有一个空序列。有5个操作,需要完成。\n- `I x`: 把$x$插入到光标之后\n- `D`: 删除光标之前的元素\n- `L`:如果光标不在最前,把光标向左移动一次\n- `R`:如果光标不在最后,把光标向右移动一次\n- `Q k`:设光标之前的序列为$a_1,a_2,\\cdots,a_n.求个数不超过$k$的最大前缀和。\n\n\n"}},{"title":"输入","value":{"format":"MD","content":"\u003cscript src\u003d\"https://cdn.bootcss.com/mathjax/2.7.0/MathJax.js\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e\n\u003cscript src\u003d\"https://cdn.bootcss.com/mathjax/2.7.0/config/TeX-AMS-MML_SVG.js\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e\n有多组测试数据。\n每组测数据,第一行一个整数$c$,接下来$c$行,每行表示一个操作。\n数据保证`Q`操作时,$k$不会超过光标前面数的个数。\n"}},{"title":"输出","value":{"format":"MD","content":"对于每个`Q`操作,输出相应的结果。"}},{"title":"样例输入","value":{"format":"MD","content":"8\nI 2\nI -1\nI 1\nQ 3\nL\nD\nR\nQ 2"}},{"title":"样例输入","value":{"format":"MD","content":"2\n3"}}]}