题目：

题解：

func canIWin(maxChoosableInteger, desiredTotal int) bool {if (1+maxChoosableInteger)*maxChoosableInteger/2 < desiredTotal {return false}dp := make([]int8, 1<<maxChoosableInteger)for i := range dp {dp[i] = -1}var dfs func(int, int) int8dfs = func(usedNum, curTot int) (res int8) {dv := &dp[usedNum]if *dv != -1 {return *dv}defer func() { *dv = res }()for i := 0; i < maxChoosableInteger; i++ {if usedNum>>i&1 == 0 && (curTot+i+1 >= desiredTotal || dfs(usedNum|1<<i, curTot+i+1) == 0) {return 1}}return}return dfs(0, 0) == 1
}