int &sub是傳入引用,可以對sub進(jìn)行修改,而int sub只是普通傳參,不能對sub賦值。 于是。。 #include using namespace std; const int m=5; int Index(int[],int n,int sub); int main(){ int b[25]={2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97}; int n=25,k,sub; for(k=0;k>sub; sub=Index(b,n,sub); if(sub!=-1) cout<<"對應(yīng)元素下標(biāo)為:"<