  During the late stage of planet formation when Mars-size cores appear,
interactions among planetary cores can excite their orbital eccentricities,
speed their merges and thus sculpture the final architecture of planet systems.
This series of work contributes to the final assembling of planet systems with
N-body simulations, including the type I and II migration of planets, gas
accretion of massive cores in a viscous disk. In this paper, the standard
formulations of type I and II migrations are adopted to investigate the
formation of planet systems around solar mass stars. Statistics on the final
distributions of planetary masses, semi-major axes and eccentricities are
derived, which are comparable to those of the observed systems. Our simulations
predict some orbital signatures of planet systems around solar mass stars: 36%
of the survival planets are giant planets (Mp>10Me). Most of the massive giant
planets (Mp>30Me) locate at 1-10AU. Terrestrial planets distribute more or less
evenly at <1-2 AU. Planets in inner orbits (<1 AU) may accumulate at the inner
edges of either the protostellar disk (3-5 days) or its MRI dead zone (30-50
days). There is a planet desert in the mass-eccecntricity diagram, i.e., lack
of planets with masses 0.005 - 0.08 MJ in highly eccentric orbits (e > 0.3 -
0.4). The average eccentricity (~ 0.15) of the giant planets (Mp>10Me) are
bigger than that (~ 0.05) of the terrestrial planets (Mp< 10Me). A planet
system with more planets tends to have smaller planet masses and orbital
eccentricities on average.
