Create 2407.longest-increasing-subsequence-ii.js

Author: everthis

2407.longest-increasing-subsequence-ii.js

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+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+const lengthOfLIS = (nums, k) => {
+  const a = nums
+    let max = Math.max(...a), st = new SegmentTreeRMQ(max + 3), res = 0;
+    for (const x of a) {
+        let l = Math.max(x-k, 0), r = x;
+        let min = st.minx(l, r), maxL = min == Number.MAX_SAFE_INTEGER ? 0 : -min;
+        maxL++;
+        res = Math.max(res, maxL);
+        st.update(x, -maxL);
+    }
+    return res;
+};
+///////////////////////////////////////////// Template ///////////////////////////////////////////////////////////
+// using array format
+function SegmentTreeRMQ(n) {
+    let h = Math.ceil(Math.log2(n)), len = 2 * 2 ** h, a = Array(len).fill(Number.MAX_SAFE_INTEGER);
+    h = 2 ** h;
+    return { update, minx, indexOf, tree }
+    function update(pos, v) {
+        a[h + pos] = v;
+        for (let i = parent(h + pos); i >= 1; i = parent(i)) propagate(i);
+    }
+    function propagate(i) {
+        a[i] = Math.min(a[left(i)], a[right(i)]);
+    }
+    function minx(l, r) {
+        let min = Number.MAX_SAFE_INTEGER;
+        if (l >= r) return min;
+        l += h;
+        r += h;
+        for (; l < r; l = parent(l), r = parent(r)) {
+            if (l & 1) min = Math.min(min, a[l++]);
+            if (r & 1) min = Math.min(min, a[--r]);
+        }
+        return min;
+    }
+    function indexOf(l, v) {
+        if (l >= h) return -1;
+        let cur = h + l;
+        while (1) {
+            if (a[cur] <= v) {
+                if (cur >= h) return cur - h;
+                cur = left(cur);
+            } else {
+                cur++;
+                if ((cur & cur - 1) == 0) return -1;
+                if (cur % 2 == 0) cur = parent(cur);
+            }
+        }
+    }
+    function parent(i) {
+        return i >> 1;
+    }
+    function left(i) {
+        return 2 * i;
+    }
+    function right(i) {
+        return 2 * i + 1;
+    }
+    function tree() {
+        return a;
+    }
+}
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+