Create 1053-previous-permutation-with-one-swap.js

Author: everthis

1053-previous-permutation-with-one-swap.js

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+/**
+ * @param {number[]} A
+ * @return {number[]}
+ */
+const prevPermOpt1 = function(A) {
+  let n = A.length, left = n - 2, right = n - 1;
+  while (left >= 0  && A[left] <= A[left + 1]) left--;
+  if (left < 0) return A;
+  while (A[left] <= A[right]) right--;
+  while (A[right - 1] == A[right]) right--;
+  swap(A,left,right)
+  return A;
+};
+function swap(a, i, j) {
+  let tmp = a[i]
+  a[i] = a[j]
+  a[j] = tmp
+}