Create LongestSubstringWithoutRepeatingCharacters.cpp

https://leetcode.com/problems/longest-substring-without-repeating-characters/

Author: itsgauravsingh

LongestSubstringWithoutRepeatingCharacters.cpp

@@ -0,0 +1,66 @@
+class Solution {
+public:
+    int lengthOfLongestSubstring(string s) {
+        int maxLen = 0;
+        int pos = 0;
+        int lastpos = -1;
+        unordered_map<char,int> m;
+        m.clear();
+        for(int i=0;i<s.length();i++) {
+            if(m.find(s[i]) != m.end()) {
+                pos = m.find(s[i])->second;
+                for(int j=pos;j>lastpos;j--) {
+                    if(m.find(s[j]) != m.end())
+                        m.erase(m.find(s[j])); 
+                }
+                lastpos = pos;
+                m.insert({s[i],i});
+            } else {
+                m.insert({s[i],i});
+            }
+            if(maxLen < m.size()) {
+                maxLen = m.size();
+            }
+        }
+        return maxLen;
+    }  
+};
+
+string stringToString(string input) {
+    assert(input.length() >= 2);
+    string result;
+    for (int i = 1; i < input.length() -1; i++) {
+        char currentChar = input[i];
+        if (input[i] == '\\') {
+            char nextChar = input[i+1];
+            switch (nextChar) {
+                case '\"': result.push_back('\"'); break;
+                case '/' : result.push_back('/'); break;
+                case '\\': result.push_back('\\'); break;
+                case 'b' : result.push_back('\b'); break;
+                case 'f' : result.push_back('\f'); break;
+                case 'r' : result.push_back('\r'); break;
+                case 'n' : result.push_back('\n'); break;
+                case 't' : result.push_back('\t'); break;
+                default: break;
+            }
+            i++;
+        } else {
+          result.push_back(currentChar);
+        }
+    }
+    return result;
+}
+
+int main() {
+    string line;
+    while (getline(cin, line)) {
+        string s = stringToString(line);
+        
+        int ret = Solution().lengthOfLongestSubstring(s);
+
+        string out = to_string(ret);
+        cout << out << endl;
+    }
+    return 0;
+}