42 lines
1004 B
Python
42 lines
1004 B
Python
import math
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# 追赶法求解
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def ZGsolve(A,b):
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n = len(b)
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beta = [0]*n
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for i in range(n):
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if i == 0:
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beta[i] = A[i][2] / A[i][1]
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else:
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beta[i] = A[i][2] / (A[i][1] - A[i][0]*beta[i-1])
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print("beta:")
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print(beta[:-1])
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for i in range(n):
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if i == 0:
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b[i] = b[i] / A[i][1]
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else:
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b[i] = (b[i] - A[i][0]*b[i-1]) / (A[i][1] - A[i][0]*beta[i-1])
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print("y:")
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print(b)
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for i in range(n-2,-1,-1):
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b[i] = b[i] - beta[i]*b[i+1]
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return b
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if __name__ == "__main__":
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##########################################################################
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#把A,b换成题干的数值###########################################
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# 储存追赶法A矩阵
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A = [
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[0,4,-1],
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[-1,4,-1],
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[-1,4,-1],
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[-1,4,-1],
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[-1,4,0]
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]
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# A第一行前面有个0，最后一行后面有个0
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b = [100,200,200,200,100]
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print("x:")
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print(ZGsolve(A,b)) |