How to pull 3 characters out of a larger string?

Say I have a string of characters, up to 100 in length. I want to search that string for the word 'the', and change it to a different 3 characters. Any thoughts on how i would go about looking at just 3 characters at a time, to find any instances of 'the' in the string?

search the string for a 't'. if you find it, see if the letter after the 't' is an 'h', then if it is, see if the letter after the 'h' is an 'e'. now you have found 'the'. you can change it now.

Use the string function strstr. It's a substring pattern match.
Example: char *s = "theologist", *t = "the";
p = strstr(s,t); // Will set p=0 because it's the address location where 't' is. If 'the' was further up the list it would return that value to p. Such as 'Netherlands' would return a 2.

#include <iostream.h>

void main(void)
{
int loop = -1;
char word[100] = "Hello the pig lives !";
while (word[loop++] != '\0') //change "the" to "one"
{
if ((word[loop] == 't') || (word[loop] == 'T'))
if ((word[loop+1] == 'h') || (word[loop+1] == 'H'))
if ((word[loop+2] == 'e') || (word[loop+2] == 'E'))
word[loop] = 'o'; word[loop+1] = 'n'; word[loop+2] = 'e';
}
cout << "\nFinsihed Product... " << word << endl;
cout << "Press A key to continue... \n"';
cin >> loop;
}

this should work but I haven't tested it. If you wanted to check and change more then one word the above method would be inefficient, it would be best to write a procedure to do it for you.