二分尋找的兩種方式

/* * query.cpp * *  Created on: 2013年8月4日 *      Author: Administrator */#include <iostream>using namespace std;class Person{string name;int age;string salary;public:Person(string name , int age , string salary):name(name),age(age),salary(salary){}friend bool operator<(const Person& a , const Person& b ){return a.name < b.name;}friend bool operator==(const Person& a ,const Person& b){return a.name == b.name;}friend ostream& operator<<(ostream& o , const Person& a){o<<"name"<<" : "<<a.name << " salary: "<<a.salary;return o;}        //以下是遞迴調用的方式friend Person* binarysearch(Person* p , int n , string name){if( n == 0 ){return NULL;}int mid = n/2;Person a(name,0,"");if(p[mid] == a){return p + mid;}else if( a < p[mid] ){return binarysearch(p,mid,name);}else{return binarysearch(p+mid+1,n - mid - 1,name);}}friend Person* binarysearch1(Person* p , int n , string name){cout<<"這時使用非遞迴版的二分尋找"<<endl;int l = 0;int r = n - 1;Person t(name,0,"");while( l <=  r){int mid = (l+r)/2;if(p[mid] == t){return p + mid;}else if( t < p[mid]  ){r = mid - 1;}else{l = mid + 1;}}return NULL;}};int main(){Person persons[3]={Person("allen",21,"40000"),Person("bllen",22,"41000"),Person("cllen",23,"42000")};cout<<"請輸入您要尋找的人的名字:";string name ;cin >> name;Person* p = binarysearch1(persons,3,name);if(p == NULL){cout<< "沒有找到"<<endl;}else{cout<< *p <<endl;}}