004 md

Author: cdToucher

note/004/README.md

@@ -47,7 +47,6 @@ The median is (2 + 3)/2 = 2.5
 
 特别地，我们选取 `m = k / 2`，下面是我画的草图，希望能帮助大家理解。
 
-![](https://raw.githubusercontent.com/Blankj/awesome-java-leetcode/master/note/004/my_draw.jpg)
 
 借助上面的理论，你能写出相关代码了吗？
 

src/me/codebase/leetcode/Test.java

@@ -1,67 +1,57 @@
 package me.codebase.leetcode;
 
-import java.util.HashMap;
-import java.util.Map;
-
 /**
  * Created by chendong on 2017/12/13.
  */
 public class Test {
 
 
     public static void main(String[] args) {
-        Integer[] arr1 = {1, 2, 3};
-        Integer[] arr2 = {2, 3, 4};
-
-        int mid1 = arr1.length / 2;
-        int mid2 = arr2.length / 2;
-    }
+        int[] A = {1, 3, 4, 6};
+        int[] B = {2, 4, 5, 8, 9, 10};
+        int[] C = {1, 2, 3, 4, 4, 5, 6, 8, 9, 10};
+        // 4.5
 
-    /*   public static int lengthOfLongestSubstring(String s) {
-           int len;
-           if (s == null || (len = s.length()) == 0) return 0;
-           int preP = 0, max = 0;
-           int[] hash = new int[128];
-           for (int i = 0; i < len; ++i) {
-               char c = s.charAt(i);
-               if (hash[c] > preP) {
-                   preP = hash[c];
-               }
-               int l = i - preP + 1;
-               hash[c] = i + 1;
-               if (l > max) max = l;
-           }
-           return max;
-       }
-   */
-    private static String distinct(String str) {
-        Map<Character, Integer> map = new HashMap<>();
-        char[] chars = str.toCharArray();
-        for (int i = 0; i < chars.length; i++) {
 
-            if (map.get(chars[i]) != null)
-                map.put(chars[i], i - map.get(chars[i]));
-            else
-                map.put(chars[i], i);
-        }
-        return null;
+        System.out.println(findMedianSortedArrays(A, B));
     }
 
 
+    /**
+     * satisfy the require which is should be O(log(m+n))
+     * <p>
+     * Array, Binary Search, Divide and Conquer
+     */
+    private static int findKth(int k, int[] A, int[] B) {
 
+        return 0;
+    }
 
-/*
-    private static String findSubString(String str, int index) {
-        char[] chars = str.toCharArray();
-        int l = 1;
-        for (int i = index; i < chars.length; i++) {
-            if (chars[i] != chars[i++]) {
-                l++;
-            }else break;
+    private static int findKth(int k, int[] arr) {
+        return 0;
+    }
+
+    public static double findMedianSortedArrays(int[] nums1, int[] nums2) {
+        int len = nums1.length + nums2.length;
+        if (len % 2 == 0) {
+            return (helper(nums1, 0, nums2, 0, len / 2) + helper(nums1, 0, nums2, 0, len / 2 + 1)) / 2.0;
         }
-        return String.valueOf()
+        return helper(nums1, 0, nums2, 0, (len + 1) / 2);
     }
-*/
 
+    private static int helper(int[] nums1, int m, int[] nums2, int n, int k) {
+        if (m >= nums1.length) return nums2[n + k - 1];
+        if (n >= nums2.length) return nums1[m + k - 1];
+        if (k == 1) return Math.min(nums1[m], nums2[n]);
+
+        int p1 = m + k / 2 - 1;
+        int p2 = n + k / 2 - 1;
+        int mid1 = p1 < nums1.length ? nums1[p1] : Integer.MAX_VALUE;
+        int mid2 = p2 < nums2.length ? nums2[p2] : Integer.MAX_VALUE;
+        if (mid1 < mid2) {
+            return helper(nums1, m + k / 2, nums2, n, k - k / 2);
+        }
+        return helper(nums1, m, nums2, n + k / 2, k - k / 2);
+    }
 
 }

src/me/codebase/leetcode/_004.java

@@ -0,0 +1,22 @@
+package me.codebase.leetcode;
+
+import java.util.Arrays;
+
+/**
+ * Created by chendong on 2018/1/2.
+ */
+public class _004 {
+
+
+    public static void main(String[] args) {
+        int[] A = {1, 3, 4, 6};
+        int[] B = {2, 4, 5, 8, 9, 10};
+        int[] C = {1, 2, 3, 4, 4, 5, 6, 8, 9, 10};
+        // 4.5
+        System.out.println(Arrays.toString(args));
+
+//        System.out.println(findMedianSortedArrays(A, B));
+    }
+
+
+}