String Convert Into Constant Char

#include<iostream>

#include <string>
using namespace std;

int main(){
string str("hello world");

const char * cstr = new char [str.length()+1];
cstr=str.c_str();

int i=0;
for(i=0;cstr[i]!='\0';i++)
    cout <<cstr[i];

cout <<endl;

system("pause");

return 0;

}