#include <iostream>using namespace std;int SeqSearch(int r[],int n,int k){ r[0]=k;//下標0用作哨兵存放要查詢的數 int i=n; while(r[i]!=k)//不用判斷下標i是否越界 {  i--; } return i;}int main(){ int n;  cout<<"請輸入數組元素個數："<<endl; cin>>n; int a[n+1]; cout<<"請輸入數組元素："<<endl; for(int i=1;i<=n;i++) {  cin>>a[i]; } int k; cout<<"請輸入要查詢的數："<<endl; cin>>k; for(int i=1;i<=n;i++) {  cout<<a[i]<<" "; } cout<<endl; cout<<"該數在數組中的位置為："; cout<<SeqSearch(a,n,k); return 0;}

#include<iostream>using namespace std;int BinSearch1(int r[],int n,int k)//非遞歸{ int low=1,high=n;//設置查找區間 while(low<=high)//如果區間存在 {  int mid=(low+high)/2;  if(k<r[mid])high=mid-1;//查找在左半區進行，回到while那一步  else if(k>r[mid])low=mid+1;  else return mid; } return 0;//如果區間不存在，則返回0，查找失敗}int BinSearch2(int r[],int low,int high,int k)//遞歸{ int mid=(low+high)/2; if(low>high) return 0; else {   if(k<r[mid])BinSearch2(r,low,mid-1,k);   else if(k>r[mid])BinSearch2(r,mid+1,high,k);   else return mid; }}int main(){ int n;  cout<<"請輸入數組元素個數："; cout<<endl; cin>>n; int a[n+1]; cout<<"請輸入數組元素："; cout<<endl; for(int i=1;i<=n;i++) {  cin>>a[i]; } cout<<"請輸入要查找的數："; cout<<endl; int k; cin>>k; cout<<"該數在數組中的位置是："<<endl; cout<<BinSearch1(a,n,k);cout<<endl; cout<<BinSearch2(a,1,n,k);}