顺序查找和折半查找

#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;

void num_rand(int A[],int N){

      srand(time(0));
    for(int i=0;i<N;i++)
        A[i]=rand()%50;

}

int somesearch(int num,int A[],int n)
{
    if(n==0)
        return -1;
    for(int index=0;index!=n;index++)
        if(A[index]==num)
        return index;

    return -1;
}

int halfsearch(int num,int A[],int n)
{
    if(n==0)
        return -1;
    int low=0,high=n-1,mid;

    while(low<high){

        mid=(low+high)/2;

        if(A[mid]==num)
             return mid;
        else if(num<A[mid])
          high=mid-1;
        else
            low=mid+1;
    }
    return -1;
}
int main()
{
    const int size=25;
    int B[size],number;

    num_rand(B,size);
    for(int i=0;i<size;i++)
        cout<<i<<":"<<B[i]<<endl;

    number=B[3];

    cout<<"Position:"<<somesearch(number,B,size)<<endl;
    cout<<"Position:"<<halfsearch(number,B,size)<<endl<<endl<<endl;

    number=B[19];

    cout<<"Position:"<<somesearch(number,B,size)<<endl;
    cout<<"Position:"<<halfsearch(number,B,size)<<endl<<endl<<endl;

    number=26;

    cout<<"Position:"<<somesearch(number,B,size)<<endl;
    cout<<"Position:"<<halfsearch(number,B,size)<<endl;
     return 0;
}