added problem 0374

Author: SHA65536

Diff for: problems/problem0374/guess_higher_lower.go

@@ -0,0 +1,28 @@
+package problem0374
+
+/*
+We are playing the Guess Game. The game is as follows:
+I pick a number from 1 to n. You have to guess which number I picked.
+Every time you guess wrong, I will tell you whether the number I picked is higher or lower than your guess.
+You call a pre-defined API int guess(int num), which returns three possible results:
+    -1: Your guess is higher than the number I picked (i.e. num > pick).
+    1: Your guess is lower than the number I picked (i.e. num < pick).
+    0: your guess is equal to the number I picked (i.e. num == pick).
+Return the number that I picked.
+*/
+
+func guessNumber(n int, guess func(int) int) int {
+	var start, mid int
+	mid = n / 2
+	for {
+		switch guess(mid) {
+		case -1:
+			n = mid - 1
+		case 1:
+			start = mid + 1
+		case 0:
+			return mid
+		}
+		mid = ((n - start) / 2) + start
+	}
+}

Diff for: problems/problem0374/guess_higher_lower_test.go

@@ -0,0 +1,39 @@
+package problem0374
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type Result struct {
+	Input    int
+	Expected int
+}
+
+var Results = []Result{
+	{10, 6},
+	{1, 1},
+	{12, 4},
+}
+
+func TestGuessHigherLower(t *testing.T) {
+	assert := assert.New(t)
+
+	for _, res := range Results {
+		n := res.Expected
+		want := res.Expected
+		guess := func(i int) int {
+			if i == n {
+				return 0
+			} else if i > n {
+				return -1
+			} else {
+				return 1
+			}
+		}
+		got := guessNumber(res.Input, guess)
+		assert.Equal(want, got, fmt.Sprintf("%+v", res))
+	}
+}

Diff for: readme.md

@@ -122,6 +122,7 @@ Each problem is in it's own directory, with test files. There are helper package
 | 0345 | [Reverse Vowels of a String](https://leetcode.com/problems/reverse-vowels-of-a-string) | [My Solution](./problems/problem0345) | ✅ |
 | 0349 | [Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays) | [My Solution](./problems/problem0349) | ✅ |
 | 0363 | [Max Sum of Rectangle No Larger Than ](https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k) | [My Solution](./problems/problem0363) | ✅ |
+| 0374 | [Guess Number Higher or Lower](https://leetcode.com/problems/guess-number-higher-or-lower) | [My Solution](./problems/problem0374) | ✅ |
 | 0376 | [Wiggle Subsequence](https://leetcode.com/problems/wiggle-subsequence) | [My Solution](./problems/problem0376) | ✅ |
 | 0377 | [Combination Sum IV](https://leetcode.com/problems/combination-sum-iv) | [My Solution](./problems/problem0377) | ✅ |
 | 0378 | [Kth Smallest Element in a Sorted Matrix](https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix) | [My Solution](./problems/problem0378) | ✅ |