clueless coding // TODO: be smarter

LeetCode 165. Compare Version Numbers: C++ Solution



Problem Statement


Compare two version numbers version1 and version2. If version1 > version2 return 1, if version1 < version2 return -1, otherwise return 0.

You may assume that the version strings are non-empty and contain only digits and the . character.

The . character does not represent a decimal point and is used to separate number sequences.

For instance, 2.5 is not “two and a half” or “half way to version three”, it is the fifth second-level revision of the second first-level revision.

Here is an example of version numbers ordering:

Function Signature (C++):
  int compareVersion(string version1, string version2)

Inputs:
  version1 = .1
  version2 = 1.1

Outputs:
-1

1.1 > 1

Inputs:
  version1 = 13.37
  version2 = 1.1

Outputs:
1

13.37 > 1



TL;DR Code Solution


int compareVersion(string version1, string version2) {

    int i = 0;
    int j = 0;
    int n1 = version1.size();
    int n2 = version2.size();

    int num1 = 0;
    int num2 = 0;
    while(i<n1 || j<n2)
    {
        while(i<n1 && version1[i]!='.'){
            num1 = num1*10+(version1[i]-'0');
            i++;
        }

        while(j<n2 && version2[j]!='.'){
            num2 = num2*10+(version2[j]-'0');;
            j++;
        }

        if(num1>num2) return 1;
        else if(num1 < num2) return -1;

        num1 = 0;
        num2 = 0;
        i++;
        j++;
    }

    return 0;

}