c_cpp 二进制搜索

Posted 2021-05-14

#include<iostream>
using namespace std;

int binary(int a[],int l,int r,int k){
    if(r>=l){
        int m=(r+l)/2;
        if (a[m]==k)
            return m;
        if (a[m]>k)
            return binary(a,l,m-1,k);
        return binary(a,m+1,r,k);
    }
    return -1;
}

int main(){
    int n;
    cout<<"Enter the no.of elements:";
    cin>>n;
    int a[n];
    cout<<"Enter the array elements:";
    for(int i=0;i<n;i++){
        cin>>a[i];
    }
    int k;
    cout<<"Enter the search element:";
    cin>>k;
    int j = binary(a,0,n-1,k);
    cout<<endl<<"--"<<j;
}