Create 2948-make-lexicographically-smallest-array-by-swapping-elements.js

Author: everthis

2948-make-lexicographically-smallest-array-by-swapping-elements.js

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+//////////////////////////// Template /////////////////////////////////
+function DJSet(n) {
+    let parent = Array(n).fill(-1);
+    return { find, union, count, equiv, par, grp }
+    function find(x) {
+        return parent[x] < 0 ? x : parent[x] = find(parent[x]);
+    }
+    function union(x, y) {
+        x = find(x);
+        y = find(y);
+        if (x == y) return false;
+        if (parent[x] < parent[y]) [x, y] = [y, x];
+        parent[x] += parent[y];
+        parent[y] = x;
+        return true;
+    }
+    function count() { // total groups
+        return parent.filter(v => v < 0).length;
+    }
+    function equiv(x, y) { // isConnected
+        return find(x) == find(y);
+    }
+    function par() {
+        return parent;
+    }
+    function grp() {
+        let groups = [];
+        for (let i = 0; i < n; i++) groups.push([]);
+        for (let i = 0; i < n; i++) groups[find(i)].push(i); // sorted and unique
+        return groups;
+    }
+}
+////////////////////////////////////////////////////////////////
+/**
+ * @param {number[]} nums
+ * @param {number} limit
+ * @return {number[]}
+ */
+var lexicographicallySmallestArray = function(nums, limit) {
+    let d = nums.map((x, i) => [x, i]).sort((x, y) => x[0] - y[0] || x[1] - y[1]), pairs = [];
+    for (let i = 1; i < nums.length; i++) {
+        if (d[i][0] - d[i - 1][0] <= limit) pairs.push([d[i - 1][1], d[i][1]]);
+    }
+    return LexicalSmallestArrayWithSwaps(nums, pairs)
+};
+
+
+// reference: https://leetcode.com/problems/smallest-string-with-swaps/
+function LexicalSmallestArrayWithSwaps (a, pairs) {
+    let n = a.length, ds = new DJSet(n), res = Array(n).fill(0);
+    for (const [x, y] of pairs) ds.union(x, y);
+    let groups = ds.grp().filter(e => e.length);
+    for (const group of groups) {
+        let ga = [];
+        for (let i of group) ga.push(a[i]);
+        ga.sort((x, y) => x - y);
+        for (let i = 0; i < group.length; i++) res[group[i]] = ga[i];
+    }
+    return res;
+};
+