<pre class="shiki github-dark shaku"><code>function canWinStonePicking(n: number): 'A' | 'B' | null { const dp =new Array(n+1).fill(false) dp[2] = true dp[3] = true for(let i =4; i&lt;n+1;i++ ){ dp[i] = !(dp[i-1] &amp;&amp; dp[i-2]) } return dp[n] == true ? "A" : "B"}</code></pre>

Dp solution, with O(n) complexity

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There is a pile of n (n > 0) stones. Player A and Player B take turns to pick 1 or 2 stones from the pile. A starts first. Who picks the last stone lo…