{"trustable":true,"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":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003eMany geometry(几何)problems were designed in the ACM/ICPC. And now, I also prepare a geometry problem for this final exam. According to the experience of many ACMers, geometry problems are always much trouble, but this problem is very easy, after all we are now attending an exam, not a contest :)\u003cbr\u003eGive you N (1\u0026lt;\u003dN\u0026lt;\u003d100) segments(线段), please output the number of all intersections(交点). You should count repeatedly if M (M\u0026gt;2) segments intersect at the same point.\u003cbr\u003e\u003cbr\u003eNote:\u003cbr\u003eYou can assume that two segments would not intersect at more than one point. \u003cbr\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"Input contains multiple test cases. Each test case contains a integer N (1\u003dN\u0026lt;\u003d100) in a line first, and then N lines follow. Each line describes one segment with four float values x1, y1, x2, y2 which are coordinates of the segment’s ending. \u003cbr\u003eA test case starting with 0 terminates the input and this test case is not to be processed.\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"For each case, print the number of intersections, and one line one case.\u003cbr\u003e"}},{"title":"Sample","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\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\u003e2\r\n0.00 0.00 1.00 1.00\r\n0.00 1.00 1.00 0.00\r\n3\r\n0.00 0.00 1.00 1.00\r\n0.00 1.00 1.00 0.000\r\n0.00 0.00 1.00 0.00\r\n0\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e1\r\n3\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}