test4 7

chenweijie · chenweijie · commit b5899be4822c · 2019-09-04T02:02:18.000+08:00
diff --git a/src/main/java/com/chen/algorithm/study/test4/Solution.java b/src/main/java/com/chen/algorithm/study/test4/Solution.java
@@ -0,0 +1,63 @@
+package com.chen.algorithm.study.test4;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author :  chen weijie
+ * @Date: 2019-09-03 23:10
+ */
+public class Solution {
+
+    public double findMedianSortedArrays(int[] nums1, int[] nums2) {
+
+        List<Integer> resultList = new ArrayList<>();
+
+
+        if (nums1 == null) {
+            for (int value : nums2) {
+                resultList.add(value);
+            }
+        } else if (nums2 == null) {
+            for (int value : nums1) {
+                resultList.add(value);
+            }
+        } else {
+
+
+
+
+        }
+
+
+        int n = resultList.size();
+
+
+        double result = 0d;
+
+        if (n % 2 == 0) {
+            result = resultList.get(resultList.size() / 2) + (resultList.get((resultList.size() / 2) - 1)) / 2;
+        } else {
+            double index = resultList.size() / 2;
+            result = resultList.get((int) Math.ceil(index));
+        }
+        return result;
+    }
+
+
+    @Test
+    public void testCase() {
+
+        int[] nums1 = {1, 2};
+        int[] nums2 = {3, 4};
+
+        double d = findMedianSortedArrays(nums1, nums2);
+        System.out.println(d);
+
+
+    }
+
+
+}
diff --git a/src/main/java/com/chen/algorithm/study/test5/Solution.java b/src/main/java/com/chen/algorithm/study/test5/Solution.java
@@ -0,0 +1,58 @@
+package com.chen.algorithm.study.test5;
+
+import org.junit.Test;
+
+/**
+ * 中心扩展算法
+ *
+ * @author :  chen weijie
+ * @Date: 2019-09-03 23:58
+ */
+public class Solution {
+
+
+    public String longestPalindrome(String s) {
+
+        if (s == null || s.length() < 1) {
+            return "";
+        }
+
+        int start = 0, end = 0;
+
+
+        for (int i = 0; i < s.length(); i++) {
+            int len1 = expandArroundCenter(s, i, i);
+            int len2 = expandArroundCenter(s, i, i + 1);
+
+            int len = Math.max(len1, len2);
+
+            if (len > end - start) {
+                //中间值-长度的一半
+                start = i - (len - 1) / 2;
+                //中间值+长度的一半
+                end = i + len / 2;
+            }
+        }
+        return s.substring(start, end + 1);
+    }
+
+
+    private int expandArroundCenter(String s, int left, int right) {
+
+        int L = left, R = right;
+        while (L >= 0 && R < s.length() && s.charAt(L) == s.charAt(R)) {
+            L--;
+            R++;
+        }
+        return R - L - 1;
+    }
+
+
+
+    @Test
+    public void testCase(){
+        System.out.println(longestPalindrome("dcacdefd"));
+    }
+
+
+}
diff --git a/src/main/java/com/chen/algorithm/study/test7/Solution.java b/src/main/java/com/chen/algorithm/study/test7/Solution.java
@@ -0,0 +1,49 @@
+package com.chen.algorithm.study.test7;
+
+import org.junit.Test;
+
+/**
+ * @author :  chen weijie
+ * @Date: 2019-09-04 01:17
+ */
+public class Solution {
+
+    public int reverse(int x) {
+
+        boolean belowZero = false;
+        Long l = Long.parseLong(x + "");
+        if (l < 0) {
+            l = Math.abs(l);
+            belowZero = true;
+        }
+
+        char[] chars = (l + "").toCharArray();
+
+        StringBuilder sb = new StringBuilder();
+        for (int i = chars.length - 1; i >= 0; i--) {
+            sb.append(chars[i]);
+        }
+
+        Long result = Long.parseLong(sb.toString());
+        if (result > 2147483647 || result <-2147483648) {
+            return 0;
+        }
+
+        if (!belowZero) {
+            return result.intValue();
+        } else {
+            return -result.intValue();
+        }
+
+    }
+
+
+    @Test
+    public void testCase() {
+        //   -2147483648~2147483647
+        System.out.println(reverse(-2143847412));
+
+    }
+
+
+}
diff --git a/src/main/java/com/chen/algorithm/study/test7/Solution2.java b/src/main/java/com/chen/algorithm/study/test7/Solution2.java
@@ -0,0 +1,35 @@
+package com.chen.algorithm.study.test7;
+
+import org.junit.Test;
+
+/**
+ * @author :  chen weijie
+ * @Date: 2019-09-04 01:51
+ */
+public class Solution2 {
+
+    public int reverse(int x) {
+        int rev = 0;
+        while (x != 0) {
+            int pop = x % 10;
+            x /= 10;
+            if (rev > Integer.MAX_VALUE / 10 || (rev == Integer.MAX_VALUE / 10 && pop > 7)) {
+                return 0;
+            }
+            if (rev < Integer.MIN_VALUE / 10 || (rev == Integer.MIN_VALUE / 10 && pop < -8)) {
+                return 0;
+            }
+            rev = rev * 10 + pop;
+        }
+        return rev;
+    }
+
+
+    @Test
+    public void testCase() {
+
+        System.out.println(reverse(9083));
+
+    }
+
+}
diff --git a/src/main/test/com/chen/test/TestDate.java b/src/main/test/com/chen/test/TestDate.java
@@ -21,6 +21,7 @@ public static void main(String[] args) {
         System.out.println("socre==="+score);
 
 
+        System.out.println(1<<31-1);
 
 
 

Original file line number	Diff line number	Diff line change
`@@ -21,6 +21,7 @@ public static void main(String[] args) {`
`21`	`21`	`System.out.println("socre==="+score);`
`22`	`22`
`23`	`23`
	`24`	`+ System.out.println(1<<31-1);`
`24`	`25`
`25`	`26`
`26`	`27`