From 7c8aba82f0fe6fc9a86f340da7d665f9e33e2394 Mon Sep 17 00:00:00 2001
From: yennanliu <f339339@gmail.com>
Date: Sun, 29 Sep 2024 19:19:52 +0800
Subject: [PATCH] update ws

---
 .../src/main/java/dev/workspace5.java         | 48 ++++++++++++++++++-
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/leetcode_java/src/main/java/dev/workspace5.java b/leetcode_java/src/main/java/dev/workspace5.java
index 891e0da2..759266fe 100644
--- a/leetcode_java/src/main/java/dev/workspace5.java
+++ b/leetcode_java/src/main/java/dev/workspace5.java
@@ -205,15 +205,59 @@ private int getDays(List<Integer> weightsList, int speed){
      *
      *
      *
-     *   idea :
+     *   idea  1:
      *     get min "x len"
      *     and get min "y len"
      *     then ans = x_len * y_len
      *
+     *  idea 2 :
+     *
+     *    hash map
+     *
+     *    {"x": [y1, y2,,,],
+     *    "y" : [x1, x2,,,,]
+     *    }
+     *
      */
     public int minAreaRect(int[][] points) {
 
-        return 0;
+        // build map
+        Map<Integer, List<Integer>> mapX = new HashMap<>();
+        Map<Integer, List<Integer>> mapY = new HashMap<>();
+
+        for (int[] point : points){
+
+            int x = point[0];
+            int y = point[1];
+
+            List<Integer> xList =  mapX.getOrDefault(x, new ArrayList<>());
+            List<Integer> yList =  mapY.getOrDefault(x, new ArrayList<>());
+
+            xList.add(x);
+            yList.add(y);
+
+            mapX.put(x, xList);
+            mapY.put(y, yList);
+        }
+
+        int res = Integer.MAX_VALUE;
+
+        for (int i = 0; i < points.length; i++){
+            for (int j = 0; j <points.length; j++){
+                int x1 = points[i][0];
+                int y1 = points[i][1];
+                int x2 = points[j][0];
+                int y2 = points[j][1];
+                // check
+                boolean canFormRectangle = (x1 != x2 && y1 != y2 && mapX.containsKey(x1) && mapX.containsKey(x2) && mapX.get(x1).equals(y2) && mapX.get(x2).equals(y1));
+                if (canFormRectangle){
+                    int area = (x2 - x1) * (y2 - y1);
+                    res = Math.min(res, area);
+                }
+            }
+        }
+
+        return res == Integer.MAX_VALUE ? 0 : res;
     }
 
 //    public int minAreaRect(int[][] points) {