add code

Author: imwwjh

.idea/uiDesigner.xml

@@ -0,0 +1,24 @@
+package BinarySearch.Q153;
+
+public class FindMinInRotatedSortedArray {
+    public int findMin(int[] nums) {
+        int left = 0;
+        int right = nums.length - 1;
+
+        while (left < right) {
+            int mid = left + (right - left) / 2;
+            if (nums[mid] > nums[right]) {
+                left = mid + 1;
+            } else {
+                right = mid;
+            }
+        }
+        return nums[left];
+    }
+
+    public static void main(String[] args) {
+        FindMinInRotatedSortedArray solution = new FindMinInRotatedSortedArray();
+        int[] nums = {4, 5, 6, 7, 0, 1, 2};
+        System.out.println("×îСԪËØÊÇ: " + solution.findMin(nums));
+    }
+}    

BinarySearch/Q153/FindMinInRotatedSortedArray.java

@@ -0,0 +1,15 @@
+package BinarySearch.Q154;
+
+class Solution {
+    public int findMin(int[] nums) {
+        int i = 0, j = nums.length - 1;
+        while (i < j) {
+            int m = (i + j) / 2;
+            if (nums[m] > nums[j]) i = m + 1;
+            else if (nums[m] < nums[j]) j = m;
+            else j--;
+        }
+        return nums[i];
+    }
+}
+

BinarySearch/Q154/Solution.java

@@ -0,0 +1,38 @@
+package BinarySearch.Q33;
+
+public class RotatedArraySearch {
+    public static int search(int[] nums, int target) {
+        int left = 0;
+        int right = nums.length - 1;
+
+        while (left <= right) {
+            int mid = left + (right - left) / 2;
+
+            if (nums[mid] == target) {
+                return mid;
+            }
+
+            // ĹĐśĎ×ó°ë˛żˇÖĘǡńÓĐĐň
+            if (nums[left] <= nums[mid]) {
+                if (target >= nums[left] && target < nums[mid]) {
+                    right = mid - 1;
+                } else {
+                    left = mid + 1;
+                }
+            } else {
+                if (target > nums[mid] && target <= nums[right]) {
+                    left = mid + 1;
+                } else {
+                    right = mid - 1;
+                }
+            }
+        }
+        return -1;
+    }
+
+    public static void main(String[] args) {
+        int[] nums = {4, 5, 6, 7, 0, 1, 2};
+        int target = 0;
+        System.out.println(search(nums, target));
+    }
+}    

BinarySearch/Q33/RotatedArraySearch.java

@@ -0,0 +1,34 @@
+package BinarySearch.Q33;
+
+class Solution {
+    public int search(int[] nums, int target) {
+        int lo = 0, hi = nums.length - 1;
+        while (lo <= hi) {
+            int mid = lo + (hi - lo) / 2;
+            if (nums[mid] == target) {
+                return mid;
+            }
+            
+            // 先根据 nums[0] 与 target 的关系判断目标值是在左半段还是右半段
+            if (target >= nums[0]) {
+                // 目标值在左半段时，若 mid 在右半段，则将 mid 索引的值改成 inf
+                if (nums[mid] < nums[0]) {
+                    nums[mid] = Integer.MAX_VALUE;
+                }
+            } else {
+                // 目标值在右半段时，若 mid 在左半段，则将 mid 索引的值改成 -inf
+                if (nums[mid] >= nums[0]) {
+                    nums[mid] = Integer.MIN_VALUE;
+                }
+            }
+
+            if (nums[mid] < target) {
+                lo = mid + 1;
+            } else {
+                hi = mid - 1;
+            }
+        }
+        return -1;
+    }
+}
+

BinarySearch/Q33/Solution.java

@@ -0,0 +1,47 @@
+package BinarySearch.Q34;
+
+public class FindTargetRange {
+    public static int[] searchRange(int[] nums, int target) {
+        int[] result = {-1, -1};
+        if (nums == null || nums.length == 0) {
+            return result;
+        }
+
+        // ²éÕÒÆðʼλÖÃ
+        int left = 0;
+        int right = nums.length - 1;
+        while (left < right) {
+            int mid = left + (right - left) / 2;
+            if (nums[mid] < target) {
+                left = mid + 1;
+            } else {
+                right = mid;
+            }
+        }
+        if (nums[left] != target) {
+            return result;
+        }
+        result[0] = left;
+
+        // ²éÕÒ½áÊøλÖÃ
+        right = nums.length - 1;
+        while (left < right) {
+            int mid = left + (right - left + 1) / 2;
+            if (nums[mid] > target) {
+                right = mid - 1;
+            } else {
+                left = mid;
+            }
+        }
+        result[1] = right;
+
+        return result;
+    }
+
+    public static void main(String[] args) {
+        int[] nums = {5, 7, 7, 8, 8, 10};
+        int target = 8;
+        int[] range = searchRange(nums, target);
+        System.out.println("[" + range[0] + ", " + range[1] + "]");
+    }
+}    

BinarySearch/Q34/FindTargetRange.java

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+package BinarySearch.Q34;
+
+class Solution {
+    public int[] searchRange (int[] nums, int target) {
+         int upper = upperBound(nums,target);
+         int low = lowerBound(nums,target);  
+         //不存在情况
+         if (upper < low) {
+             return new int[]{-1,-1};
+         }
+         return new int[]{low,upper};
+    }
+    //计算下边界
+    int lowerBound(int[] nums, int target) {
+        int left = 0, right = nums.length - 1;
+        while (left <= right) {
+            //这里需要注意，计算mid
+            int mid = left + ((right - left) >> 1);
+            if (target <= nums[mid]) {
+                //当目标值小于等于nums[mid]时，继续在左区间检索，找到第一个数
+                right = mid - 1;
+
+            }else if (target > nums[mid]) {
+                //目标值大于nums[mid]时，则在右区间继续检索，找到第一个等于目标值的数
+                left = mid + 1;
+
+            }
+        }
+        return left;
+    }
+    //计算上边界
+    int upperBound(int[] nums, int target) {
+        int left = 0, right = nums.length - 1;
+        while (left <= right) {          
+            int mid = left + ((right - left) >> 1);
+            if (target >= nums[mid]) {
+                 left = mid + 1;               
+            }else if (target < nums[mid]) {
+                right = mid - 1;
+            }            
+        }
+        return right;
+    }
+}
+