{"trustable":false,"prependHtml":"\u003cstyle type\u003d\"text/css\"\u003e\n section pre {\n display: block;\n padding: 9.5px;\n margin: 0 0 10px;\n font-size: 13px;\n line-height: 1.42857143;\n word-break: break-all;\n word-wrap: break-word;\n color: #333;\n background: rgba(255, 255, 255, 0.5);\n border: 1px solid #ccc;\n border-radius: 6px;\n }\n\u003c/style\u003e\n\u003cscript\u003e\n window.katexOptions \u003d {\n delimiters: [\n {left: \u0027\\\\(\u0027, right: \u0027\\\\)\u0027, display: false},\n {left: \u0027\\\\[\u0027, right: \u0027\\\\]\u0027, display: true}\n ]\n };\n\u003c/script\u003e\n","sections":[{"title":"Problem Statement","value":{"format":"HTML","content":"\u003cp\u003e雷巨巨农场里的牛牛想要学习, 可惜牛牛的学力参差不齐, 并且每只牛牛只想走与学力相当的路程去找学伴, 雷巨巨为了让牛牛充分锻炼提升肉质, 又想提高牛牛的智商, 决定让两只牛牛相向而行,恰好走的路程之和就是这两只牛牛的学力之和. \u003c/p\u003e\n\u003cp\u003e雷巨巨一共有 \u003cvar\u003eN\u003c/var\u003e只牛牛, 牛牛们的栏位在一条直线上, 相邻的栏位距离为\u003cvar\u003e1\u003c/var\u003e, 聪明的你能帮雷巨巨所有符合上述要求的牛牛学伴对吗"}},{"title":"Constraints","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e \n\u003cul\u003e \n \u003cli\u003e输入均为正整数\u003c/li\u003e \n \u003cli\u003e第一行一个整数\u003cvar\u003eN, 1 \u003c N \u003c 100000\u003c/var\u003e\u003c/li\u003e\n \u003cli\u003e第二行\u003cvar\u003eN\u003c/var\u003e个整数\u003cvar\u003eA_i, 0 \u003c A_i \u003c 1000000000\u003c/var\u003e , 表示牛牛的学力\u003c/li\u003e\n\u003c/ul\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e \n\u003cp\u003e输出满足条件的牛牛对数\u003c/p\u003e"}},{"title":"Sample Input 1","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e\n\u003cpre\u003e6\n2 3 3 1 3 1\n\u003c/pre\u003e"}},{"title":"Sample Output 1","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e\n\u003cpre\u003e3\n\u003c/pre\u003e \n"}},{"title":"Sample Input 2","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e\n\u003cpre\u003e6\n5 2 4 2 8 8\n\u003c/pre\u003e"}},{"title":"Sample Output 2","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e\n\u003cpre\u003e0\n\u003c/pre\u003e "}},{"title":"Sample Input 3","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e\n\u003cpre\u003e32\n3 1 4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6 2 6 4 3 3 8 3 2 7 9 5\n\u003c/pre\u003e"}},{"title":"Sample Output 3","value":{"format":"HTML","content":"\u003ch3\u003e\u003c/h3\u003e\n\u003cpre\u003e22\n\u003c/pre\u003e"}}]}