Create 2763-sum-of-imbalance-numbers-of-all-subarrays.js

Author: everthis

2763-sum-of-imbalance-numbers-of-all-subarrays.js

@@ -0,0 +1,72 @@
+class MultiSet {
+  constructor() {
+    this.countMap = new Map()
+    this.valueList = []
+  }
+  remove(value) {
+    if(!this.countMap.has(value)) return false
+    let index = binarySearch(this.valueList, value)
+    if (this.countMap.get(value) === 1) {
+      this.valueList.splice(index, 1)
+      this.countMap.delete(value)
+    } else {
+      this.countMap.set(value, (this.countMap.get(value) || 0) - 1)
+    }
+    return true
+  }
+  add(value) {
+    let index = binarySearch(this.valueList, value)
+    if (index < 0) {
+      this.valueList.splice(-index - 1, 0, value)
+      this.countMap.set(value, 1)
+    } else {
+      this.countMap.set(value, this.countMap.get(value) + 1)
+    }
+  }
+  has(value) {
+    return this.countMap.has(value)
+  }
+  get max() {
+    return this.valueList[this.valueList.length - 1]
+  }
+  get min() {
+    return this.valueList[0]
+  }
+}
+
+function binarySearch(arr, val) {
+  let l = 0, r = arr.length
+  while( l < r ) {
+    const mid = Math.floor((l + r) / 2)
+    if(arr[mid] < val) {
+       l = mid + 1
+    } else {
+      r = mid
+    }
+  }
+  if(arr[l] !== val) return -(l + 1)
+  
+  return l
+}
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+const sumImbalanceNumbers = function (nums) {
+  let n = nums.length, res = 0;
+  for (let i = 0; i < n; i++) {
+      let tree = new MultiSet(), cnt = 0;
+      tree.add(nums[i]);
+      for (let j = i + 1; j < n; j++) {
+          let x = nums[j];
+          if (!tree.has(x)) {
+              tree.add(x);
+              cnt++;
+              if (tree.has(x - 1)) cnt--;
+              if (tree.has(x + 1)) cnt--;
+          }
+          res += cnt;
+      }
+  }
+  return res;
+}