Completed expression calc and stretch

Author: Wayleom Vargas Rubio

lesson_06/expression/src/abbre-stretch-wayvar.ts

@@ -1,30 +1,26 @@
 function isValidAlphaAbbreviation(word: string, abbr: string): boolean {
-
     if (word.length < 1 || word.length > 25) return false;
     if (abbr.length < 1 || abbr.length > 15) return false;
     if (!/^[a-z]+$/.test(word)) return false;
     if (!/^[a-z]+$/.test(abbr)) return false;
-    if (abbr.length > word.length) return false;
-
-    let built = "";
-    let i = 0;
-
-    while (i < word.length) {
-        const ch = word[i];
-
-        built += ch;
-        i++;
-
-        if (i < word.length) {
-        const skip = ch.charCodeAt(0) - 96;
-        i += skip; 
+    
+    let wordIndex: number = 0;
+    let i: number = 0;
+    
+    while (i < abbr.length && wordIndex < word.length) {
+        const ch: string = abbr[i]; // Process abbreviation, not word
+        
+        if (word[wordIndex] === ch) {
+            // Literal character match
+            wordIndex++;
+            i++;
+        } else {
+            // Character represents a number - skip that many characters
+            const skip: number = ch.charCodeAt(0) - 96; // a=1, b=2, etc.
+            wordIndex += skip;
+            i++;
         }
     }
-
-return built === abbr;
-}
-console.log(isValidAlphaAbbreviation("abbreviation", "acefn")); // true
-console.log(isValidAlphaAbbreviation("abbreviation", "acehn")); // false
-console.log(isValidAlphaAbbreviation("abbreviation", "acgn")); // false
-console.log(isValidAlphaAbbreviation("internationalization", "imzdn")); // true
-console.log(isValidAlphaAbbreviation("internationalization", "inz")); // false
+    
+    return wordIndex === word.length && i === abbr.length;
+}