$2.\backslash ((10\backslash$mathrm$\{$pts$\})\backslash )$ Given an array of integers, write an efficient algorithm to check whether there is a sub$-$array whose sum is a multiple of a given integer $\backslash ($ K $\backslash ).$ You must use a strategy of computing prefix$-$sums. Give a detailed analysis of the runtime or expected runtime of your algorithm. $($Java$)$