Create 3298-count-substrings-that-can-be-rearranged-to-contain-a-string-ii.js

Author: everthis

3298-count-substrings-that-can-be-rearranged-to-contain-a-string-ii.js

@@ -0,0 +1,49 @@
+/**
+ * @param {string} word1
+ * @param {string} word2
+ * @return {number}
+ */
+var validSubstringCount = function (word1, word2) {
+  const mp1 = new Array(26).fill(0)
+  const mp2 = new Array(26).fill(0)
+  let count = 0
+
+  for (const c of word2) {
+    mp1[c.charCodeAt(0) - 'a'.charCodeAt(0)]++
+  }
+
+  for (let i = 0; i < 26; i++) {
+    if (mp1[i] > 0) {
+      count += mp1[i]
+    }
+  }
+
+  let res = 0
+  let left = 0
+
+  for (let right = 0; right < word1.length; right++) {
+    mp2[word1.charCodeAt(right) - 'a'.charCodeAt(0)]++
+    if (
+      mp1[word1.charCodeAt(right) - 'a'.charCodeAt(0)] > 0 &&
+      mp2[word1.charCodeAt(right) - 'a'.charCodeAt(0)] <=
+        mp1[word1.charCodeAt(right) - 'a'.charCodeAt(0)]
+    ) {
+      count--
+    }
+
+    while (count === 0) {
+      res += word1.length - right
+      if (
+        mp1[word1.charCodeAt(left) - 'a'.charCodeAt(0)] > 0 &&
+        mp2[word1.charCodeAt(left) - 'a'.charCodeAt(0)] <=
+          mp1[word1.charCodeAt(left) - 'a'.charCodeAt(0)]
+      ) {
+        count++
+      }
+      mp2[word1.charCodeAt(left) - 'a'.charCodeAt(0)]--
+      left++
+    }
+  }
+
+  return res
+}