Usaco orz
Time Limit: 5000/1500 MS (Java/others) memory limit: 32768/32768 K (Java/Others)
Total submission (s): 1099 accepted submission (s): 398
Problem descriptionlike everyone, cows enjoy variety. Their current fancy is new shapes for pastures. The old rectangular shapes are out of favor; new geometries are the favorite.
I. m. hei, the lead cow pasture regular ect, is in charge of creating a triangular pasture surrounded by nice white fence rails. she is supplied with N fence segments and must arrange them into a triangular pasture. ms. hei must use all the rails to create three sides of non-zero length. calculating the number of different kinds of pastures, she can build that enclosed with all fence segments.
Two pastures look different if at least one side of both pastures has different lengths, and each pasture shocould not be degeneration.
Inputthe first line is an integer T (t <= 15) indicating the number of test cases.
The first line of each test case contains an integer n. (1 <= n <= 15)
The next line contains N integers Li indicating the length of each fence segment. (1 <= LI <= 10000)
Outputfor each test case, output one integer indicating the number of different pastures.
Sample input1 3 2 3 4
Sample output1
Source2012 ACM/ICPC Asia Regional Changchun online
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It is just a search. It is still a smooth question in the Changchun cyber competition.
Search questions... It's better.
I use map to determine the weight, and pay attention to a few places to cut, otherwise it will be TLE.
# Include <stdio. h> # Include <Math. h> # Include <Iostream> # Include <Algorithm> # Include <Map> Using Namespace STD; Const Int Maxn = 20 ; Int A [maxn]; Map < Long Long , Int > MP; Int Tol; Int N; Int SUM; Void DFS ( Int L1, Int L2,Int L3, Int I ){ If (L1> L2) Swap (L1, L2 ); If (L1> L3) Swap (L1, L3 ); If (L2> L3) Swap (L2, L3 ); If (L3 * 2 > Sum) Return ; If (I =N ){ If (L1 + L2> L3 ){ Long Long T = L1 * 150000 * 150000 + L2 * 150000 + L3; If (MP [T] = 0 ) {MP [T] = 1 ; Tol ++ ;}} Return ;} Int T11 = l1 + A [I + 1 ]; Int T12 = L2; Int T13 = L3; If (T11> T12) Swap (T11, T12 ); If (T11> T13) Swap (T11, t13 ); If (T12> T13) Swap (T12, t13); DFS (T11, T12, t13, I + 1 ); Int T21 = L1; Int T22 = l2 + A [I + 1 ]; Int T23 = L3; If (T21> T22) Swap (T21, T22 ); If (T21>T23) Swap (T21, T23 ); If (T22> T23) Swap (T22, T23 ); If (T11! = T22 | T12! = T22 | t13! = T23) DFS (T21, T22, T23, I + 1 ); Int T31 = L1; Int T32 = L2; Int T33 = L3 + A [I + 1 ]; If (T31>T32) Swap (t31, T32 ); If (T31> T33) Swap (t31, t33 ); If (T32> T33) Swap (T32, t33 ); If (T31! = T11 | T32! = T12 | t33! = T13) If (T31! = T21 | T32! = T22 | t33! = T23) DFS (t31, T32, t33, I + 1 );} Int Main (){ Int T; scanf ( " % D " ,& T ); While (T -- ) {Scanf ( " % D " ,& N); sum = 0 ; For ( Int I =1 ; I <= N; I ++) {scanf ( " % D " , & A [I]); sum + = A [I];} MP. Clear (); Tol = 0 ; DFS ( 0 , 0 , 0 , 0 ); Printf ( " % D \ n " , Tol );} Return 0 ;}