题目：

题解：

func calculateMinimumHP(dungeon [][]int) int {
    n, m := len(dungeon), len(dungeon[0])
    dp := make([][]int, n + 1)
    for i := 0; i < len(dp); i++ {
        dp[i] = make([]int, m + 1)
        for j := 0; j < len(dp[i]); j++ {
            dp[i][j] = math.MaxInt32
        }
    }
    dp[n][m - 1], dp[n - 1][m] = 1, 1
    for i := n - 1; i >= 0; i-- {
        for j := m - 1; j >= 0; j-- {
            minn := min(dp[i+1][j], dp[i][j+1])
            dp[i][j] = max(minn - dungeon[i][j], 1)
        }
    }
    return dp[0][0]
}

func min(x, y int) int {
    if x < y {
        return x
    }
    return y
}

func max(x, y int) int {
    if x > y {
        return x
    }
    return y
}