Update 765-couples-holding-hands.js

Author: everthis

765-couples-holding-hands.js

@@ -72,3 +72,35 @@ const minSwapsCouples = function (row) {
   }
 }
 
+// another
+
+/**
+ * @param {number[]} row
+ * @return {number}
+ */
+const minSwapsCouples = function (row) {
+  let res = 0
+  const n = row.length
+  const ptn = Array(n).fill(0), pos = Array(n).fill(0)
+  
+  for(let i = 0; i < n; i++) {
+    ptn[i] = (i % 2 === 0 ? i + 1 : i - 1)
+    pos[row[i]] = i
+  }
+
+  for (let i  = 0; i < n ;i++) {
+    for (let j = ptn[pos[ptn[row[i]]]]; i != j; j = ptn[pos[ptn[row[i]]]]) {
+			swap(row, i, j);
+			swap(pos, row[i], row[j]);
+			res++;
+		}
+  }
+  
+  return res
+
+  function swap(arr, i, j) {
+    const val = arr[i]
+    arr[i] = arr[j]
+    arr[j] = val
+  }
+}