292 Time Limit Exceeded

Author: aQua

Algorithms/0292.nim-game/README.md

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+# [292. Nim Game](https://leetcode.com/problems/nim-game/)
+
+## 题目
+
+You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the winner. You will take the first turn to remove the stones.
+
+Both of you are very clever and have optimal strategies for the game. Write a function to determine whether you can win the game given the number of stones in the heap.
+
+For example, if there are 4 stones in the heap, then you will never win the game: no matter 1, 2, or 3 stones you remove, the last stone will always be removed by your friend.
+
+Credits:Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.
+
+## 解题思路
+
+见程序注释

Algorithms/0292.nim-game/nim-game.go

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+package Problem0292
+
+func canWinNim(n int) bool {
+	if n <= 3 {
+		return true
+	}
+
+	return !canWinNim(n-1) || !canWinNim(n-2) || !canWinNim(n-3)
+}

Algorithms/0292.nim-game/nim-game_test.go

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+package Problem0292
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// tcs is testcase slice
+var tcs = []struct {
+	n   int
+	ans bool
+}{
+
+	{4, false},
+	{5, true},
+	{41, true},
+
+	// 可以有多个 testcase
+}
+
+func Test_canWinNim(t *testing.T) {
+	ast := assert.New(t)
+
+	for _, tc := range tcs {
+		fmt.Printf("~~%v~~\n", tc)
+		ast.Equal(tc.ans, canWinNim(tc.n), "输入:%v", tc)
+	}
+}
+
+func Benchmark_canWinNim(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, tc := range tcs {
+			canWinNim(tc.n)
+		}
+	}
+}