int main(int n, char *v)
{    
    char *p1 = "hello";
    char *p2 = "hello";
    p2[0] = '0';    
    if(p1 == p2)
        printf("equal\n");
    else
        printf("not equal\n");
    printf("%s", p1);
    return 0;
}

A>int main(int n, char *v)
A>{    
A>    char *p1 = "hello";
A>    char *p2 = "hello";
A>    p2[0] = '0';    
A>    if(p1 == p2)
A>        printf("equal\n");
A>    else
A>        printf("not equal\n");
A>    printf("%s", p1);
A>    return 0;
A>}
A>

p2[0] = '0';

A>    char *p1 = "hello";
A>    char *p2 = "hello";
A>

char *p1 = "hello";

char *p2 = "hello";

const char *p2 = "hello";

const char *p2 = "hello";
char *p1 = p2;

char *p2 = "hello";

A>char *p2 = "hello";
A>

A string literal (2.13.4) that is not a wide string literal can be converted to an rvalue of type “pointer to char”; a wide string literal can be converted to an rvalue of type “pointer to wchar_t”. In either case, the result is a pointer to the first element of the array. This conversion is considered only when there is an explicit appropriate pointer target type, and not when there is a general need to convert from an lvalue to an rvalue. [Note: this conversion is deprecated. See Annex D. ] For the purpose of ranking in overload resolution (13.3.3.1.1), this conversion is considered an array-to-pointer conversion followed by a qualification conversion (4.4). [Example: "abc" is converted to “pointer to const char” as an array-to-pointer conversion, and then to “pointer to char” as a qualification conversion. ]

D.4 Implicit conversion from const strings [depr.string]
1 The implicit conversion from const to non-const qualification for string literals (4.2) is deprecated.