  We report observations of CP violation in the decays B0 -> K+pi- and B0 ->
pi+pi- in a sample of 383 million Y(4S) -> BBbar events. We find 4372 +/- 82 B0
-> K+pi- decays and measure the direct CP-violating charge asymmetry Akpi =
-0.107 +/- 0.018 (stat) +0.007-0.004 (syst), which excludes the CP-conserving
hypothesis with a significance of 5.5 standard deviations. In the same sample
we find 1139 +/- 49 B0 -> pi+pi- decays and measure the CP-violating
asymmetries Spipi = -0.60 +/- 0.11 (stat) +/- 0.03 (syst) and Cpipi = -0.21 +/-
0.09 (stat) +/- 0.02 (syst). CP conservation in B0 -> pi+pi- (Spipi=Cpipi=0) is
excluded at a confidence level 1-C.L. = 8 * 10^{-8}, corresponding to 5.4
standard deviations.
