О работе new, почему выходит ошибка?

#include <iostream>
using namespace std;
 
int main(){
  int i = 99;
  char *p = new char[1];
  char *u = new char[100];
  copy(p, p+i, u);
  delete [] p;
  p = new char[100];
  copy(u, u+i, p);
  delete [] u;
 
  do {
    p = new (p) char [160];  // If we change 160 to 100 : p = new (p) char [100]; 
    p[i+30]='s';                    // and 30 to 0 :  p[i]='s'; 
  }
  while (--i);
  p[0] = 's';
 
 cout<<p;
 delete [] p;
 
 i=10;
 while (--i)
 cout<<"\n DEL "<<p[i]<<' '<<i;
 
}

#include <iostream>
#include <cstdio>
 
using namespace std;
 
char *getline() {
    int i = 0;
    char * tmp = new char[1];
 
    while (cin.get(tmp[i]) && (tmp[i] != '\n') && tmp[i] != EOF && tmp[i] != '\0') {
        i++;
        tmp[i] = '\0';
 
    cout<<' '<<tmp<<'\n',
        tmp = new (tmp) char[i];
    }
 
    return tmp;
}
 
 
int main(){
char *p = getline();
cout<<p;
delete [] p;
cout<<'D'<<p;
}