Create 3261-count-substrings-that-satisfy-k-constraint-ii.js

Author: everthis

3261-count-substrings-that-satisfy-k-constraint-ii.js

@@ -0,0 +1,72 @@
+/**
+ * @param {string} s
+ * @param {number} k
+ * @param {number[][]} queries
+ * @return {number[]}
+ */
+var countKConstraintSubstrings = function(s, k, queries) {
+    let binaryString = s, maxZerosOnes = k, queriesList = queries
+    let length = binaryString.length;
+    let zeroPrefixSum = Array(length + 1).fill(0);
+
+    for (let idx = 0; idx < length; idx++) {
+        zeroPrefixSum[idx + 1] = (binaryString[idx] === '0' ? 1 : 0) + zeroPrefixSum[idx];
+    }
+
+    let endIndex = Array(length).fill(0);
+
+    for (let start = 0; start < length; start++) {
+        let end = start;
+        let low = start, high = length - 1;
+
+        while (low <= high) {
+            let mid = low + Math.floor((high - low) / 2);
+            let zeroCount = zeroPrefixSum[mid + 1] - zeroPrefixSum[start];
+            let oneCount = mid + 1 - start - zeroCount;
+
+            if (zeroCount <= maxZerosOnes || oneCount <= maxZerosOnes) {
+                end = mid;
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+        }
+        endIndex[start] = end;
+    }
+
+    for (let i = 0; i < length; i++) {
+        zeroPrefixSum[i + 1] = (endIndex[i] - i + 1) + zeroPrefixSum[i];
+    }
+
+    let results = [];
+
+    /* Template by Bharadwaj ( LEETCODE JAVASCRIPT ) */
+    /* Youtube : https://youtube.com/@code-with-Bharadwaj */
+    /* Portfolio : https://manu-bharadwaj-portfolio.vercel.app/ */
+
+    for (let query of queriesList) {
+        let left = query[0];
+        let right = query[1];
+        let validIndex = left - 1;
+        let low = left, high = right;
+        let totalCount = 0;
+
+        while (low <= high) {
+            let mid = low + Math.floor((high - low) / 2);
+
+            if (endIndex[mid] < right) {
+                validIndex = mid;
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+        }
+
+        totalCount += zeroPrefixSum[validIndex + 1] - zeroPrefixSum[left];
+        let difference = right - validIndex;
+        totalCount += (difference * (difference + 1)) / 2;
+        results.push(totalCount);
+    }
+
+    return results;
+};