refactor: Improve space complexity

Author: mike2ox

house-robber/mike2ox.ts

@@ -11,14 +11,15 @@ function rob(nums: number[]): number {
   if (nums.length === 1) return nums[0];
   if (nums.length === 2) return Math.max(nums[0], nums[1]);
 
-  const dp: number[] = new Array(nums.length);
-
-  dp[0] = nums[0];
-  dp[1] = Math.max(nums[0], nums[1]);
+  let prev = nums[0];
+  let maxResult = Math.max(nums[0], nums[1]);
+  let current = 0;
 
   // 남은 집을 순회하면서 최대값을 구함
-  for (let i = 2; i < nums.length; i++)
-    dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]);
-
-  return dp[nums.length - 1];
+  for (let i = 2; i < nums.length; i++) {
+    current = Math.max(maxResult, prev + nums[i]);
+    prev = maxResult;
+    maxResult = current;
+  }
+  return maxResult;
 }