C++编写通讯录（简单解法但有一定缺陷）

#include<iostream>
#include<string>
using namespace std;
struct One{
	char name[10];
	int age;
	char sex[10];
	char phone[12];
	char address[20];
};
void fun1(One *one,int *sum);
void fun2(One one[],int sum);
void fun3(One one[],int sum);
void fun4(One one[],int sum);
void fun5(One one[],int sum);
void fun6(One one[],int sum);
void fun7();
int main()
{
	int choice;
	int sum=0;
	while(1)
	{
	One one[1000];
    cout<<"1,添加联系人"<<endl;
	cout<<"2,显示联系人"<<endl;
	cout<<"3,删除联系人"<<endl;
	cout<<"4,查找联系人"<<endl;
	cout<<"5,修改联系人"<<endl;
	cout<<"6,清空"<<endl; 
	cout<<"7,退出通讯录"<<endl; 
	if(sum<1000)
	{
		cin>>choice;
		switch(choice)
		{
			case 1:fun1(&one[sum],&sum);
				break;
			case 2:fun2(one,sum);
				break;
			case 3:fun3(one,sum);
				break;
			case 4:fun4(one,sum);
				break;
			case 5:fun5(one,sum);
				break;
			case 6:fun6(one,sum);
				break;
			case 7:fun7();
				break;
		}		
	}
	}
	return 0;
}
void fun1(One *one,int *sum)
{
	
	cout<<"输入名字"<<endl;
	cin>> one->name;
	cout<<"输入年龄"<<endl;
	cin>> one->age;
	cout<<"输入性别"<<endl;
	cin>> one->sex;
	cout<<"输入电话"<<endl;
	cin>> one->phone;
	cout<<"输入地址"<<endl;
	cin>> one->address;
	(*sum)++;
}
void fun2(One one[],int sum)
{
	int i=0;
	for(i=0;i<=(sum-1);i++)
	{
		if(one[i].age!=-1)
		{
		cout<<"名字："<<one[i].name<<"\t";
		cout<<"年龄："<<one[i].age<<"\t";
		cout<<"性别："<<one[i].sex<<"\t";
		cout<<"电话："<<one[i].phone<<"\t";
		cout<<"地址："<<one[i].address<<"\t";
		cout<<endl;
	}
	}
}
void fun3(One one[],int sum)
{
	int i,n;
	string a;
	cout<<"你要删除:"<<endl;
	cin>>a;
	for(i=0;i<sum;i++)
	{
		if(a==one[i].name)
		{
			n=i;
			for(i=n;i<sum;i++)
			{
				one[i]=one[i+1];
			}
		}
	} 
   one[sum-1].age=-1;
}
void fun4(One one[],int sum)
{
   int i;
   string a;
   cout<<"你要查找:"<<endl;
   cin>>a;
   for(i=0;i<sum;i++)
	{
		if(a==one[i].name)
		{
		cout<<"名字："<<one[i].name<<"\t";
		cout<<"年龄："<<one[i].age<<"\t";
		cout<<"性别："<<one[i].sex<<"\t";
		cout<<"电话："<<one[i].phone<<"\t";
		cout<<"地址："<<one[i].address<<"\t";
		cout<<endl;
		}	
    }
}
void fun5(One one[],int sum)
{
	cout<<"你要修改:"<<endl;
	int i;
	string a;
	 cin>>a;
   for(i=0;i<sum;i++)
	{
	if(a==one[i].name)
	{
	cout<<"输入名字"<<endl;
	cin>> one[i].name;
	cout<<"输入年龄"<<endl;
	cin>> one[i].age;
	cout<<"输入性别"<<endl;
	cin>> one[i].sex;
	cout<<"输入电话"<<endl;
	cin>> one[i].phone;
	cout<<"输入地址"<<endl;
	cin>> one[i].address;
    }
	}
}
void fun6(One one[],int sum)
{
	int i=0;
	for(i=0;i<sum;i++)
	{
	 one[i].age=-1;
    }
	cout<<"清除成功!"<<endl;
}
void fun7()
{
	cout<<"退出成功！"<<endl;
}