题目：
题解：
func convertToTitle(columnNumber int) string {ans := []byte{}for columnNumber > 0 {columnNumber--ans = append(ans, 'A'+byte(columnNumber%26))columnNumber /= 26}for i, n := 0, len(ans); i < n/2; i++ {ans[i], ans[n-1-i] = ans[n-1-i], ans[i]}return string(ans)
}
)
)
