赵子龙一身是胆
程序猿遍体皆肝

题目

Write a program that outputs the string representation of numbers from 1 to n.

But for multiples of three it should output “Fizz” instead of the number and for the multiples of five output “Buzz”. For numbers which are multiples of both three and five output “FizzBuzz”.

Example:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

n = 15,

Return:
[
    "1",
    "2",
    "Fizz",
    "4",
    "Buzz",
    "Fizz",
    "7",
    "8",
    "Fizz",
    "Buzz",
    "11",
    "Fizz",
    "13",
    "14",
    "FizzBuzz"
]

题目

Given a non-empty array of integers, every element appears twice except for one. Find that single one.

Note:

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

Example 1:

1
2

Input: [2,2,1]
Output: 1

Example 2:

1
2

Input: [4,1,2,1,2]
Output: 4

题目

Write a function that reverses a string. The input string is given as an array of characters char[].

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

You may assume all the characters consist of printable ascii characters.

Example 1:

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2

Input: ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

1
2

Input: ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]

题目

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase.

Example 1:

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2

Input: "Hello"
Output: "hello"

Example 2:

1
2

Input: "here"
Output: "here"

Example 3:

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2

Input: "LOVELY"
Output: "lovely"

题目

You’re given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in S is a type of stone you have. You want to know how many of the stones you have are also jewels.

The letters in J are guaranteed distinct, and all characters in J and S are letters. Letters are case sensitive, so "a" is considered a different type of stone from "A".

Example 1:

1
2

Input: J = "aA", S = "aAAbbbb"
Output: 3

Example 2:

1
2

Input: J = "z", S = "ZZ"
Output: 0

Note:

S and J will consist of letters and have length at most 50.
The characters in J are distinct.