{"trustable":false,"prependHtml":"\u003cstyle type\u003d\"text/css\"\u003e\n #problem-body \u003e 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","sections":[{"title":"","value":{"format":"HTML","content":"\u003chtml\u003e\n \u003chead\u003e\u003c/head\u003e\n \u003cbody\u003e\n \u003cdiv id\u003d\"problem-body\"\u003e \n \u003cp\u003eGiven an array a of N integers a1, a2, a3, ... aN you have to find the longest alternating sub-sequence of this array . \u003cbr\u003e An alternating sequence b1, b2 ... bk, k\u0026gt;\u003d1 is a sequence that has the 2 following properties:\u003cbr\u003e 1.|b1|\u0026lt;|b2|\u0026lt;|b3|\u0026lt;.....\u0026lt;|bk|\u003cbr\u003e 2. The signs alternate between adjacent elements, i.e, if b1 \u0026gt; 0 then b2\u0026lt;0, b3 \u0026gt;0 and so on. Alternatively, if b1\u0026lt;0, then b2\u0026gt;0, b3\u0026lt;0 and so on. \u003cbr\u003e A sub sequence of array a is a sequence obtained by dropping some elements of the array a. Here is the formal definition. \u003cbr\u003e It is guaranteed that the array a contains no element equal to 0. \u003c/p\u003e \n \u003ch3\u003eConstraints\u003c/h3\u003e \n \u003cp\u003e 1\u0026lt;\u003dN\u0026lt;\u003d5000 |Ai|\u0026lt;\u003d10^9, Ai not equal to 0. \u003c/p\u003e \n \u003ch3\u003eInput\u003c/h3\u003e \n \u003cp\u003eThe first line contains a single integer N, denoting the size of the array. The next line contains N integers , denoting the array a. \u003c/p\u003e \n \u003ch3\u003eOutput\u003c/h3\u003e \n \u003cp\u003ePrint a single integer - the length of the longest alternating sub-sequence. \u003c/p\u003e \n \u003ch3\u003eExample\u003c/h3\u003e \n \u003cpre\u003e\n\u003cb\u003eInput:\u003c/b\u003e\n8\n1 2 -2 -3 5 -7 -8 10\n\n\u003cb\u003eOutput:\u003c/b\u003e\n5\n\u003c/pre\u003e \n \u003ch3\u003eExplaination\u003c/h3\u003e \n \u003ch4\u003e One of the longest alternating subsequence is 1 -2 5 -7 10 \u003c/h4\u003e \n \u003c/div\u003e\n \u003c/body\u003e\n\u003c/html\u003e"}}]}