A Rhode Island city that has struggled with deficits and cash-flow problems is reporting that it ended the last fiscal year with its first surplus in several years. Mayor Donald Grebien of Pawtucket announced the welcome news Monday. He said an independent audit showed the city ended fiscal year 2012 $2.7 million in the black. The money will be transferred to the city’s reserve fund, which had dropped to nearly zero following years of fiscal challenges. The city’s current budget totals $109 million. It is the city’s first surplus since fiscal 2008.