chore(Blind): add answer key and solutions for deduction problems

work/Blind/deduction.js

@@ -0,0 +1,82 @@
+// ============================================================
+// BLIND DEDUCTION SET — Monday evening, ONE round, then stop.
+// The 6 core interview problems, disguised exactly as they'd
+// appear Tuesday: no statement, just input => output pairs.
+// Rules: deduce the rule, SAY it in one sentence out loud,
+// state the plan (freq map? sort? tiebreak?), then implement.
+// Do NOT open blind-deduction-answers.js until finished.
+// Target: rule stated < 3 min, implemented < 6 min each.
+// ============================================================
+
+// ---- problem1 ----
+// problem1([8, 1, 2, 2, 3])   => [4, 0, 1, 1, 3]
+// problem1([6, 5, 4, 8])      => [2, 1, 0, 3]
+// problem1([7, 7, 7, 7])      => [0, 0, 0, 0]
+// problem1([3, 1, 2])         => [2, 0, 1]
+// problem1([5])               => [0]
+// problem1([4, 1, 4, 1])      => [2, 0, 2, 0]
+function problem1(arr) {
+  // your code
+}
+
+// ---- problem2 ----
+// problem2("tree")            => "eert"
+// problem2("cccaaa")          => "aaaccc"
+// problem2("Aabb")            => "bbaA"
+// problem2("z")               => "z"
+// problem2("bookkeeper")      => "eeekkoobpr"
+// problem2("mississippi")     => "iiiissssppm"
+function problem2(str) {
+  // your code
+}
+
+// ---- problem3 ----
+// problem3([1, 1, 2, 2, 2, 3])           => [3, 1, 1, 2, 2, 2]
+// problem3([2, 3, 1, 3, 2])              => [1, 3, 3, 2, 2]
+// problem3([-1, 1, -6, 4, 5, -6, 1, 4, 1]) => [5, -1, 4, 4, -6, -6, 1, 1, 1]
+// problem3([9])                          => [9]
+// problem3([5, 5, 4, 4])                 => [5, 5, 4, 4]
+function problem3(arr) {
+  // your code
+}
+
+// ---- problem4 ----
+// problem4("leetcode")        => 0
+// problem4("loveleetcode")    => 2
+// problem4("aabb")            => -1
+// problem4("x")               => 0
+// problem4("aabbc")           => 4
+// problem4("aa")              => -1
+function problem4(str) {
+  // your code
+}
+
+// ---- problem5 ----
+// problem5("anagram", "nagaram")  => true
+// problem5("rat", "car")          => false
+// problem5("a", "ab")             => false
+// problem5("", "")                => true
+// problem5("aacc", "ccac")        => false
+// problem5("listen", "silent")    => true
+function problem5(s, t) {
+  // your code
+}
+
+// ---- problem6 ----
+// problem6([1, 1, 1, 2, 2, 3], 2)        => [1, 2]
+// problem6([1], 1)                       => [1]
+// problem6([4, 4, 4, 6, 6, 7, 7, 7, 7], 2) => [7, 4]
+// problem6([5, 5, 5, 5], 1)              => [5]
+// problem6([3, 0, 1, 0], 1)              => [0]
+// problem6([2, 2, 3, 3, 1], 3)           => [2, 3, 1]
+function problem6(arr, k) {
+  // your code
+}
+
+// ---- harness: uncomment per problem after implementing ----
+// console.log(problem1([8, 1, 2, 2, 3]), problem1([4, 1, 4, 1]));
+// console.log(problem2("tree"), problem2("bookkeeper"));
+// console.log(problem3([2, 3, 1, 3, 2]), problem3([5, 5, 4, 4]));
+// console.log(problem4("loveleetcode"), problem4("aabbc"));
+// console.log(problem5("anagram", "nagaram"), problem5("aacc", "ccac"));
+// console.log(problem6([4, 4, 4, 6, 6, 7, 7, 7, 7], 2), problem6([2, 2, 3, 3, 1], 3));