guess number higher or lower

fishercoder1534 · fishercoder1534 · commit 9febd2e59cf3 · 2016-10-25T20:56:36.000-07:00
diff --git a/EASY/src/easy/GuessNumberHigherorLower.java b/EASY/src/easy/GuessNumberHigherorLower.java
@@ -0,0 +1,37 @@
+package easy;
+
+public class GuessNumberHigherorLower {
+    /**The core problem/trouble to solve this problem is to figure out the problem description:
+     * this API: guess(int num) means to take your guess num and let you know if your guessed num is bigger or smaller than the answer.
+     * That's why if num > target, it returns -1 which means the target is smaller than your guess!!!*/
+
+    public int guessNumber(int n) {
+        int left = 1, right = n;
+        while(left+1 < right){
+            int mid = left + (right-left)/2;
+            int g = guess(mid);
+            if(g == 0) return mid;
+            else if(g > 0) left = mid;
+            else right = mid;
+        }
+        if(guess(left) == 0) return left;
+        return right;
+    }
+
+    /**This is a fake guess method that I wrote just to compile/test, I'll have to change it to another number other than 6 based on the number to be found.*/
+    private int guess(int num) {
+        if(num > 6){
+            return -1;
+        } else if(num < 6){
+            return 1;
+        } else {
+            return 0;
+        }
+    }
+    
+    public static void main(String...strings){
+        GuessNumberHigherorLower test = new GuessNumberHigherorLower();
+        System.out.println(test.guessNumber(10));
+    }
+
+}
diff --git a/README.md b/README.md
@@ -12,6 +12,7 @@
 |388|[Longest Absolute File Path](https://leetcode.com/problems/longest-absolute-file-path/)|[Solution](../../blob/master/MEDIUM/src/medium/LongestAbsoluteFilePath.java)| O(n)|O(d) | Medium| Stack
 |387|[First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string/)|[Solution](../../blob/master/EASY/src/easy/FirstUniqueCharacterinaString.java)| O(n)|O(n) | Easy| HashMap
 |386|[Lexicographical Numbers](https://leetcode.com/problems/lexicographical-numbers/)|[Solution](../../blob/master/MEDIUM/src/medium/LexicographicalNumbers.java)| O(n)|O(1) | Medium| 
+|374|[Guess Number Higher or Lower](https://leetcode.com/problems/guess-number-higher-or-lower/)|[Solution](../../blob/master/EASY/src/easy/GuessNumberHigherorLower.java)| O(logn)|O(1) | Easy| Binary Search
 |350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/)|[Solution](../../blob/master/EASY/src/easy/IntersectionOfTwoArraysII.java)| O(m+n)|O((m+n)) could be optimized | Easy| HashMap, Binary Search
 |349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/)|[Solution](../../blob/master/EASY/src/easy/IntersectionOfTwoArrays.java)| O(m+n)|O(min(m,n)) | Easy| Two Pointers, Binary Search
 |325|[Maximum Size Subarray Sum Equals k](https://leetcode.com/problems/maximum-size-subarray-sum-equals-k/)|[Solution] | O(n)|O(n) | Medium| HashMap
