string compare in c++

#include <iostream>
#include <cstring>

using namespace std;

int main()
{
    char *p[4]={"avc","sdf","dfs","eft"};
    char ad[5];
    cout << "input the book name" << endl;
    cin>> ad;
    int i=0;
    while(i<4){

    if((strcmp(ad,p[i]))==0){

    cout<<"book is available in item= "<<i;
    }
    else
    cout<<"\nbook is not available in item "<<i;
    i++;
    }

    return 0;
}