已知数列\(\left\{ {{a}_{n}} \right\}\)是等比数列，数列\(\left\{ {{b}_{n}} \right\}\)满足\({{b}_{1}}=-3,{{b}_{2}}=-6,{{a}_{n+1}}+{{b}_{n}}=n(n\in {{N}_{+}})\)．

\((1)\)求\(\left\{ {{a}_{n}} \right\}\)的通项公式；

\((2)\)求数列\(\left\{ {{b}_{n}} \right\}\)的前\(n\)项和\({{S}_{n}}\)．