Add 3 in c language

Author: julienChemillier

c/3-Longest-Substring-Without-Repeating-Characters.c

@@ -0,0 +1,28 @@
+/*
+Given a string s, find the length of the longest substring without repeating characters.
+Time: O(n)
+Space: O(1)
+*/
+
+int max(int a, int b) {
+    return a>b?a:b;
+}
+
+int lengthOfLongestSubstring(char * s){
+    int alpha[128] = {0};
+    int i=0;
+    int j=0;
+    int ans=0;
+    while (s[j]!='\0') {
+        alpha[s[j]]++;
+        if (alpha[s[j]]>1) {
+            while (alpha[s[j]]>1) {
+                alpha[s[i]]--;
+                i++;
+            }
+        }
+        ans = max(ans, j-i+1);
+        j++;
+    }
+    return ans;
+}