CareerCup

string str1 ;
string str2;
int l_1 = str1.length();
int l_2 = str2.length();

if (l_1 != l_2)
{
      printf("false\n");
}
else
{
      int i;
      int flag = 0;
      for(i = 0; i < l_1; i++)
      {
             if( str1[i] != str2[i])
             {
	            flag = 0;
                    break;
	     }
	     else
	      {
		     flag = 1;
	      }
      }
      if ( flag == 0)
      {
	     printf("false\n");
      }
      else
      {
	     printf("yes\n");
      }
}

If this is how the question was phrased, I would first clarify what is the goal of the comparison. Are we trying to find how similar/dis-similar, or just a simple true/false if they are exact or not? Also, is our comparison case-sensitive?

For this example I will use the following assumtions:

1. We want a true/false based on an exact match of the length/characters
2. Our comparison is indeed case sensitive (boo != Boo)

In my below example, I convert Java String to a character array so that the algorithm is applicable to other languages and not cluttered with Java's built-in String functions. Simply put, the algorithm for string comparison is:

1. Check for equal length, if not then return false.
2. Check sequentially through each array comparing 1 char at a time, if any are different then return false
3. If 1 and 2 both clear without returning false, then return true as they are the same.

public boolean compareStrings(String s1, String s2){
	char[] first = s1.toArray();
	char[] second = s2.toArray();

	if(first.length != second.length){
		return false;
	}
	
	for(int i = 0; i < first.length; i++){
		if(first[i] != second[i]){
			return false;
		}
	}
	
	return true
}