HDU 2047 percent-wire split plane (split plane)

polyline split planeTime limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others)
Total submission (s): 24706 Accepted Submission (s): 16782

problem Descriptionwe've seen a lot of straight-line split-plane problems, and this topic is slightly different today, and we're asking for the maximum number of n-polyline split planes. For example, a polyline can divide the plane into two parts, and a maximum of two polylines can be divided into 7 parts, as shown below.
 
Inputthe first line of the input data is an integer c, representing the number of test instances, followed by the C row of data, each line containing an integer n (0<n<=10000), representing the number of polylines.

Outputfor each test instance, output the maximum number of partitions for the plane, and the output for each instance takes up one row.

Sample Input

212

 Sample Output

27

 AuthorLCY The following:

When the line splits the plane, increments the n+1 polygon set X (n) is the maximum number of planes that can be divided by n lines, x (n) =x (n-1) +n and x (1) = 2; push n=1,2,3,4,...., x (n) =2,4,7,11,... N (n+1) /2+1; When you are a node of a polyline, L (n) =x (2n) -2n, because each additional 1 polylines, adds 2 straight lines, each more vertex, less than 2 faces in the case of a straight line. So the formula is introduced: 2*n*n-n+1.

AC Code:

HDU 2047 percent-wire split plane (split plane)