binary_search.cpp

// binary_search

#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;

struct Rule
{
    bool operator() (const int & a1, const int & a2) const {
        return a1%10 < a2%10; // 按个位数从小到大排序
    }
};

void Print(int a[], int size)
{
    for (int i=0; i<size; ++i)
    {
        cout << a[i] << ",";
    }
    cout << endl;
}

int main()
{
    int a[] = {12,45,3,98,21,7};
    sort(a,a+6);
    Print(a,6);
    cout<<"result:"<<binary_search(a,a+6,12)<<endl; // 可以查找到，返回1
    cout<<"result:"<<binary_search(a,a+6,77)<<endl; // 无法查找到，返回0
    sort(a,a+6,Rule());
    Print(a,6);
    cout<<"result:"<<binary_search(a,a+4,7,Rule())<<endl; // 不包含下标为4的元素，返回0
    cout<<"result:"<<binary_search(a,a+5,7,Rule())<<endl; // 包含下标为4的元素，返回1
    return 0;
}