@@ -42,9 +42,69 @@ function non_repeat_substring(str) {
4242 return maxLength ;
4343}
4444
45- console . log ( non_repeat_substring ( "aabccbb" ) ) ;
46- console . log ( non_repeat_substring ( "abbbb" ) ) ;
47- console . log ( non_repeat_substring ( "abccde" ) ) ;
45+ // console.log(non_repeat_substring("aabccbb"));
46+ // console.log(non_repeat_substring("abbbb"));
47+ // console.log(non_repeat_substring("abccde"));
48+ console . log ( non_repeat_substring ( "abcdaefghijkl" ) , "#0" ) ;
49+ 50+ // -------- Alternate Solution ----------
51+ // The above solution algo fails for last testcase. The 2 solutions below are correct.
52+ 53+ // Solution 1
54+ function noRepeatCharLen1 ( str ) {
55+ let j = 0 ;
56+ let i = 0 ;
57+ const frequencyTracker = { } ;
58+ let longestSubStrLen = 0 ;
59+ 60+ while ( j < str . length ) {
61+ if ( ! frequencyTracker . hasOwnProperty ( str [ j ] ) ) {
62+ frequencyTracker [ str [ j ] ] = 1 ;
63+ longestSubStrLen = Math . max ( longestSubStrLen , j - i + 1 ) ;
64+ } else {
65+ frequencyTracker [ str [ j ] ] ++ ;
66+ }
67+ 68+ while ( frequencyTracker [ str [ j ] ] > 1 ) {
69+ frequencyTracker [ str [ i ] ] --
70+ if ( frequencyTracker [ str [ i ] ] === 0 ) {
71+ delete frequencyTracker [ str [ i ] ] ;
72+ }
73+ 74+ i ++ ;
75+ }
76+ 77+ j ++ ;
78+ } ;
79+ 80+ return longestSubStrLen ;
81+ }
82+ 83+ // Solution #2
84+ function noRepeatCharLen2 ( str ) {
85+ let windowStart = 0 ,
86+ maxLength = 0 ,
87+ charIndexMap = { } ;
88+ 89+ for ( let windowEnd = 0 ; windowEnd < str . length ; windowEnd ++ ) {
90+ const rightChar = str [ windowEnd ] ;
91+ 92+ if ( rightChar in charIndexMap ) {
93+ windowStart = Math . max ( windowStart , charIndexMap [ rightChar ] + 1 ) ;
94+ }
95+ 96+ charIndexMap [ rightChar ] = windowEnd ;
97+ 98+ maxLength = Math . max ( maxLength , windowEnd - windowStart + 1 ) ;
99+ }
100+ 101+ return maxLength ;
102+ }
103+ 104+ console . log ( noRepeatCharLen1 ( "abcdaefghijkl" ) , "#1" ) ;
105+ console . log ( noRepeatCharLen2 ( "abcdaefghijkl" ) , "#2" ) ;
106+ 107+ // a b c d a e f g h i j k l
48108
49109/*
50110Time Complexity #
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