http://oj.leetcode.com/problems/longest-substring-without-repeating-characters/ Calculating the length of the longest substring without duplicated characters Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length…

lengthOfLongestSubstring.cpp

#include <string>
#include <map>
#include <iostream>

using namespace std;

class Solution 
{
public:
	int lengthOfLongestSubstring(string s) 
	{
		// IMPORTANT: Please reset any member data you declared, as
		// the same Solution instance will be reused for each test case.

		if (s.length() == 0)
			return 0;

		if (s.length() == 1)
			return 1;

		unsigned int maxLength = 0;
		unsigned int start = 0;
		unsigned int i = 0;

		while (i < s.length())
		{
			bool existing = false;
			unsigned int j = start;

			for (j = start; j < i; j++)
			{
				if (s[j] == s[i])
				{
					existing = true;
					break;
				}
			}

			if (!existing)
			{
				i++;
			}
			else
			{
				maxLength = (maxLength < i - start) ? i - start : maxLength;
				start = j + 1;
			}
		}

		maxLength = (maxLength < i - start) ? i - start : maxLength;

		return maxLength;
	}
};

int _tmain(int argc, _TCHAR* argv[])
{
	Solution s;
	int result = -1;
	string str;

	str = "";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	str = "a";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	str = "ab";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	str = "aa";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	str = "abc";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	str = "aba";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	str = "abcbabccbaedfg";
	result = s.lengthOfLongestSubstring(str);
	cout << "[" << str << "]" << endl;
	cout << result << endl;

	return 0;
}