Codechef June 2013 Predictopus

Was wondering for a while if the each test case is accumulative from the previous...turned out it was not. Accepted!

	# Let p = probability that team A win
	# M = amount of rupees bet on team A
	# R = number of rupees = 10000
	# E = max expected rupees
	# Hence,
	# R-M = number of rupees bet on team B
	# 1-p = probability that team B wins
	# Expected rupees
	# = p(M + M * (2-2p)) + (1-p)((R-M) + (R-M) * (2-2(1-p)))
	# = pM + pM(2-2p) + (1-p)(R-M) + (1-p)(R-M)(2p)
	# = pM + 2pM -2ppM + R-Rp -M +pM + (2p-2pp)(R-M)
	# = 4pM - 2ppM +R-Rp-M + 2pR - 2ppR -2pM +2ppM
	# = 2pM + R -Rp - M + 2pR - 2ppR
	# = 2pM + R - M + pR - 2ppR
	# = M(2p-1) + R - pR - 2ppR
	# For each case, p and R are constant.
	# Take the derivative of E against M
	# to find value of M which E is greatest
	# That value = 2p-1.
	# If p > 0.5, increasing M will increase E
	# If p < 0.5, increasing M will decrease E
	# Hence if p > 0.5 bet everything on team A
	# else if p < 0.5 bet everything on team B
	# Verification: expected rupees
	# = p[M( 1 + (2-2p))] + (1-p)[(R-M)(1+2p)]
	# = pM(3 - 2p) + (R-M) (1+p-2pp)
	# = 3pM - 2ppM + R + Rp - 2ppR - M - pM + 2ppM
	# = 2pM + R + Rp - 2ppR - M
	# = pM - M + pM + R + Rp - 2ppR
	# = M(p-1) + pM + R(1+p-2pp)
	import sys
	T = int(sys.stdin.readline().strip())
	R = 10000
	for i in range(T):
	p = float(sys.stdin.readline().strip())
	if p > 0.5:
	print(p*(R+R*(2-2*p)))
	else:
	print((1-p)*(R+R*2*p))

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