{"trustable":true,"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":"\u003cdiv id\u003d\"problem-body\"\u003e\n\t\u003cp\u003eYou\u0027re given a sequence \u003cstrong\u003es\u003c/strong\u003e of \u003cstrong\u003eN\u003c/strong\u003e distinct integers.\u003cbr\u003eConsider all the possible sums of three integers from the sequence at three different indices.\u003cbr\u003eFor each obtainable sum output the number of different triples of indices that generate it.\u003cbr\u003e\u003cstrong\u003e\u003cbr\u003eConstraints:\u003c/strong\u003e\u003cbr\u003eN \u0026lt;\u003d 40000, |s\u003csub\u003ei\u003c/sub\u003e| \u0026lt;\u003d 20000\u003c/p\u003e\r\n\u003ch3\u003eInput\u003c/h3\u003e\r\n\u003cp\u003eThe first line of input contains a single integer N.\u003cbr\u003eEach of the next N lines contain an element of s.\u003c/p\u003e\r\n\u003ch3\u003eOutput\u003c/h3\u003e\r\n\u003cp\u003ePrint the solution for each possible sum in the following format:\u003cbr\u003esum_value : number_of_triples\u003cbr\u003e\u003cbr\u003eSmaller sum values should be printed first.\u003c/p\u003e\r\n\u003ch3\u003eExample\u003c/h3\u003e\r\n\u003cdiv\u003e\u003ctable class\u003d\"vjudge_sample\"\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\u003e5\n-1\n2\n3\n0\n5\n\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e1 : 1\n2 : 1\n4 : 2\n5 : 1\n6 : 1\n7 : 2\n8 : 1\n10 : 1\u003cstrong\u003e\n\u003c/strong\u003e\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\r\n\u003cp\u003e\u003cstrong\u003eExplanation:\u003c/strong\u003e\u003cbr\u003e4 can be obtained using triples ( 0, 1, 2 ) and ( 0, 3, 4 ).\u003cbr\u003e7 can be obtained using triples ( 0, 2, 4 ) and ( 1, 3, 4 ).\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eNote:\u003c/strong\u003e a triple is considered the same as any of its permutations.\u003c/p\u003e\n\u003c/div\u003e"}}]}