importsys# Matrix Ai has dimension p[i-1] x p[i] for i = 1..ndefMatrixChainOrder(p,n):# For simplicity of the program, one extra row and one# extra column are allocated in m[][]. 0th row and 0th# column of m[][] are not usedm=[[0forxinrange(n)]forxinrange(n)]# O(n^2)# m[i,j] = Minimum number of scalar multiplications needed# to compute the matrix A[i]A[i+1]...A[j] = A[i..j] where# dimension of A[i] is p[i-1] x p[i]# cost is zero when multiplying one matrix.foriinrange(1,n):#O(n) + O(n^2)m[i][i]=0# L is chain length.forLinrange(2,n):foriinrange(1,n-L+1):# O(n^2)j=i+L-1m[i][j]=float('inf')#จำนวนเต็มบวกที่ใหญ่ที่สุดที่รองรับโดยจำนวนเต็มปกติของ Python นี่คืออย่างน้อย 2 ** 31-1 จำนวนเต็มลบที่ใหญ่ที่สุดคือ -maxint-1 - ผลลัพธ์ที่ไม่สมมาตรจากการใช้เลขคณิตไบนารีเสริมของ 2forkinrange(i,j):# O(n^2)* O(n) = O(n^3)# q = cost/scalar multiplicationsq=m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]ifq<m[i][j]:m[i][j]=qreturnm[1][n-1]# Driver program to test above functionarr=[1,2,3,4]size=len(arr)print("Minimum number of multiplications is "+str(MatrixChainOrder(arr,size)))# best case = O(n^3)# worst case = O(n^3)
การค, ณล, กโซ, ของเมทร, กซ, matrix, chain, multiplication, หร, การค, ณเมตร, กซ, ใช, สำหร, บการแก, ญหาการค, matrix, งการค, ณปกต, อาจจะม, จำนวนคร, งมากเก, นไปหร, อม, ประส, ทธ, ภาพท, ไม, พอซ, งการใช, algorithm, เป, นการค, matrix, อย, างต, อเน, องเพ, อหาร, ปแบบการ. Matrix Chain Multiplication hrux karkhunemtriks ichsahrbkaraekpyhakarkhun matrix sungkarkhunpktixaccamicanwnkhrngmakekiniphruxmiprasiththiphaphthiimdiphxsungkarich algorithm niepnkarkhun matrix xyangtxenuxngephuxharupaebbkarkhunthidithisudodyichkhunsmbtikarepliynhmwdhmukarkhunkhxng matrixtwxyangmatrix X mikhnad 10 x 3matrix Y mikhnad 3 x 5matrix Z mikhnad 5 x 6 canwnkhrngkhxngkarkhunaebb X Y Z khux 10 3 5 10 5 6 450 khrngswncanwnkhrngkhxngkarkhunaebb X Y Z khux 3 5 6 10 3 6 270 khrng caehnidwakarepliynhmwdhmukarkhunchwyephimprasiththiphaphhruxldcanwnkhrngkarkhunlngid eracungtxngharupaebbkhxnghmwdhmuthidithisudodyich Matrix Chain Multiplication thakarkhun thaeratxngkarkhunaemthrikscanwn n tw A1A2 An txngkarhaladbkarkhunaemthriks thiichcanwnkhrngkhxngkarkhunnxythisudechn n 3 txngkarkhun A1A2A3 emux A1 A2 A3 mikhnad10x100 100x5 aela 5x50tamladb A1A2 A3 txngichcanwnkhrngkhxngkarkhun 10 100 5 ephuxkhanwn A1A2 10 5 50 ephuxkhanwn A1A2 A3 7 500 khrng A1 A2A3 txngichcanwnkhrngkhxngkarkhun 100 5 50 ephuxkhanwn A2A3 10 100 50 ephuxkhanwn A1 A2A3 75 000 khrngcaehnidwa A1A2 A3 ichcanwnkhrngkhxngkarkhunnxykwa A1 A2A3 thungsibethaimport sys Matrix Ai has dimension p i 1 x p i for i 1 n def MatrixChainOrder p n For simplicity of the program one extra row and one extra column are allocated in m 0th row and 0th column of m are not used m 0 for x in range n for x in range n O n 2 m i j Minimum number of scalar multiplications needed to compute the matrix A i A i 1 A j A i j where dimension of A i is p i 1 x p i cost is zero when multiplying one matrix for i in range 1 n O n O n 2 m i i 0 L is chain length for L in range 2 n for i in range 1 n L 1 O n 2 j i L 1 m i j float inf canwnetmbwkthiihythisudthirxngrbodycanwnetmpktikhxng Python nikhuxxyangnxy 2 31 1 canwnetmlbthiihythisudkhux maxint 1 phllphththiimsmmatrcakkarichelkhkhnitibnariesrimkhxng 2 for k in range i j O n 2 O n O n 3 q cost scalar multiplications q m i k m k 1 j p i 1 p k p j if q lt m i j m i j q return m 1 n 1 Driver program to test above function arr 1 2 3 4 size len arr print Minimum number of multiplications is str MatrixChainOrder arr size best case O n 3 worst case O n 3 https www youtube com watch v GMzVeWpyTN0 1 https www geeksforgeeks org dynamic programming set 8 matrix chain multiplication 1 xangxingphidphlad mipayrabu lt ref gt sahrbklumchux https www youtube com watch v GMzVeWpyTN0 aetimphbpayrabu lt references group https www youtube com watch v GMzVeWpyTN0 gt thisxdkhlxngkn hruximmikarpid lt ref gt xangxingphidphlad mipayrabu lt ref gt sahrbklumchux https www geeksforgeeks org dynamic programming set 8 matrix chain multiplication aetimphbpayrabu lt references group https www geeksforgeeks org dynamic programming set 8 matrix chain multiplication gt thisxdkhlxngkn hruximmikarpid lt ref gt ekhathungcak https th wikipedia org w index php title karkhunlukoskhxngemthriks amp oldid 7624087, wikipedia, วิกิ หนังสือ, หนังสือ, ห้องสมุด,