二分尋找演算法遞迴和非遞迴實現（C++）__web

二分尋找演算法代碼：

#include<iostream>  using namespace std;  //非遞迴實現  int FindElement(int a[],int first,int end,int target)  {      int mid,value;      int L=first,R=end;      while(L<R)      {          mid=(L+R)/2;          value=a[mid];          if(value==target)          {              return mid;          }          if(target<value)          {  if(R-L==1){return -1;}            R=mid;          }          else          {  if(a[R]==target){return target;}if(R-L==1){return -1;}            L=mid;          }      }      return -1;  }  //遞迴實現  int Findelement(int a[],int first,int end,int target)  {      int mid;      int L=first,R=end;      mid=(L+R)/2;      if(a[mid]==target)      {          return mid;      }      if(mid==end||mid==0)      {          return -1;      }      if(a[mid]>target)      {  if(a[R]==target){return target;}        R=mid;          return Findelement(a,L,R,target);      }      else      {  if(R-L==1){return -1;}        L=mid;          return Findelement(a,L,R,target);      }  }  int main()  {      int a[10];      for(int i=0;i<10;i++)      {          a[i]=i*2;      }      int n=Findelement(a,0,10,7);      if(n>=0&&n<10)          cout<<a[n];elsecout<<"can't find this element!"<<endl;    cout<<endl;      n=FindElement(a,0,10,7);      if(n>=0&&n<10)          cout<<a[n];else cout<<"can't find this element!"<<endl;    return 0;  }