接收用户输入的10个数,完成如下操作:
(1)接收用户输入的1个数,运用二分查找法查找该数是否在数据序列中;
(2)要求编写二分查找的递归算法和非递归算法,并分别进行测试。
#include<iostream>
using namespace std;
//自己完成二分查找的递归和非递归算法
//非递归二分查找算法
int twoFind1(int A[], int len, int K)
{
int low = 0, high = len - 1,middle;
if (low > high) return -2;
while (low <= high)//包含等于的情况
{
middle = (low + high) / 2;
if (K == A[middle]) return middle;
else if (K > A[middle]) low = middle + 1;
else high = middle - 1;
}
return -1;
}
int twoFind2(int A[], int len, int K)
{
int low = 0, high = len - 1,middle;
if (low > high) return -2;
while (low < high)//不含等于的情况,并在最后做判断
{
middle = (low + high) / 2;
if (K == A[middle]) return middle;
else if (K > A[middle]) low = middle + 1;
else high = middle - 1;
}
if (low == high && A[low] == K) return low;
return -1;
}
//递归二分查找算法
int twoFind3(int A[], int k, int low, int high)
{
int middle=0;
if (low > high) return -1;
middle = (low + high) / 2;
if (low==high && A[middle] == k) return middle;
if (low < high) {
if (A[middle] < k) return twoFind3(A, k, middle + 1, high);
else if(A[middle]==k) return middle;
else return twoFind3(A, k, 0, middle - 1);
}
return -1;
}
void Init_A(int *A,int n)
{
int value = 0;
cout << "请用户输入10个数据:" << endl;
for (int i = 0; i < n; i++)
{
cin >> value;
A[i] = value;
}
}
int main()
{
int k = 0,m=0,l=0;
int * A = new int[10];
Init_A(A,10);
int len = 10;
cout << "非递归测试1:" << endl;
cout << "要查找的元素值为:"; cin >> k;
cout << "所查找元素在数组中的位置为第:" << twoFind1(A, len,k) + 1 << "个" << endl;
cout << "非递归测试2:" << endl;
cout << "要查找的元素值为:"; cin >> l;
cout << "所查找元素在数组中的位置为第:" << twoFind2(A, len,l) + 1 << "个" << endl;
cout << "递归算法测试:" << endl;
cout << "要查找的元素值为:"; cin >> m;
cout << "所查找元素在数组中的位置为第:" << twoFind3(A, m, 0, len - 1) + 1 << "个" << endl;
}