Stretch file

Author: dxbenson252

lesson_06/devynbenson/dev_function.ts

@@ -0,0 +1,62 @@
+function isValidAlphaAbbreviation(word: string, abbr: string): boolean {
+  let i = 0; // pointer for word
+  let j = 0; // pointer for abbr 
+  let prevWasSkip = true;
+
+
+
+  // Helper: convert 'a'..'z' → 1..26
+  function alphaToNum(ch: string): number {
+    return ch.charCodeAt(0) - 'a'.charCodeAt(0) + 1;
+  }
+
+  // Helper: check if this is a skip letter
+  function isSkipLetter(ch: string): boolean {
+    if (ch.length !== 1) return false;
+    const num = alphaToNum(ch);
+    return num >= 1 && num <= 26;
+  }
+  
+  
+    while (j < abbr.length && i < word.length) {
+        const ch = abbr[j];
+        if (!prevWasSkip) {
+
+            if (isSkipLetter(ch)) {
+                const skipCount = alphaToNum(ch);
+                if (i + skipCount > word.length) {
+                    return false; // Skip goes beyond word length
+                }
+              
+
+                prevWasSkip = true;
+                j++;
+                i+= skipCount; // Skip ahead in abbr
+                
+                continue;
+            } else {
+                return false; // Invalid abbreviation
+            }
+        }
+
+        else if (word[i] === ch) {
+            i++;
+            j++;
+            prevWasSkip = false;
+        } else {
+            return false; // Mismatch found
+        }
+    }
+
+  
+  return true;
+}
+
+// --- test harness skeleton ---
+console.log('a'.charCodeAt(0));  // What number do you get?
+console.log('b'.charCodeAt(0));  // What about this one?
+console.log('z'.charCodeAt(0));  // And this?
+console.log(isValidAlphaAbbreviation("internationalization", "imzdn")); // expect true
+console.log(isValidAlphaAbbreviation("substitution", "sjn")); // expect true
+console.log(isValidAlphaAbbreviation("substitution", "seen")); // expect false
+console.log(isValidAlphaAbbreviation("test", "ab")); // expect false