2. 給定一陣列 a[10]={ 1, 3, 9, 2, 5, int f (int a[], int n) {8, 4, 9, 6, 7 },i.e., a[0]=1,a[1]=3, …, a[8]=6, a[9]=7,以 f(a, 10)呼叫執行右側 for (int i=1; i<=n-1; i=i+1) {函式後,回傳值為何?