CareerCup1.8.cpp

CareerCup1.8.cpp

/* Chapter 1
 * 1.8 Assume you have a method isSubstring which checks if one word is
 * a substring of another. Given two strings, s1 and s2, write code to
 * check if s2 is a rotation of s1 using only one call to isSubstring
 * (e.g. "waterbottle" is a rotation of "erbottlewat")
 */

#include <iostream>
#include <string>

using namespace std;

bool isSubstring(string s1, string s2);   // Return true if s2 is substring of s1

bool isRotation(string s1, string s2) {
    // First, the length must be the same
    // Second, the rotation cut point must make s1 into xy
    //         s2 = yx (rotation). Check if s2 is substring of s1s1:
    //         yx isSub of xyxy? if yes, return true;else return false.
    if (s1.size() == s2.size() && isSubstring(s1 + s1, s2) {
        return true;
    } else {
        return false;
    }
}

// Main Function
int main(int argc, char const *argv[])
{
    string s1 = "waterbottle";
    string s2 = "erbottlewat";
    isRotation(s1, s2)    
    return 0;
}