Code – 第74页

[Python] L1-001. Hello World-PAT团体程序设计天梯赛GPLT

这道超级简单的题目没有任何输入。

你只需要在一行中输出著名短句“Hello World!”就可以了。

PS：感谢github用户@zhuzihao-hz提供的pull request～

print('Hello World!')

1	print('Hello World!')

[swift] LeetCode 832. Flipping an Image

Given a binary matrix A, we want to flip the image horizontally, then invert it, and return the resulting image.

To flip an image horizontally means that each row of the image is reversed. For example, flipping [1, 1, 0] horizontally results in [0, 1, 1].

To invert an image means that each 0 is replaced by 1, and each 1 is replaced by 0. For example, inverting [0, 1, 1] results in [1, 0, 0].

Example 1:

Input: [[1,1,0],[1,0,1],[0,0,0]]
Output: [[1,0,0],[0,1,0],[1,1,1]]
Explanation: First reverse each row: [[0,1,1],[1,0,1],[0,0,0]].
Then, invert the image: [[1,0,0],[0,1,0],[1,1,1]]

Example 2:

Input: [[1,1,0,0],[1,0,0,1],[0,1,1,1],[1,0,1,0]]
Output: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]
Explanation: First reverse each row: [[0,0,1,1],[1,0,0,1],[1,1,1,0],[0,1,0,1]].
Then invert the image: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]

Notes:

1 <= A.length = A[0].length <= 20
0 <= A[i][j] <= 1

return A.map({$0.map({1-$0}).reversed()})

1	return A.map({$0.map({1-$0}).reversed()})

[swift] LeetCode 804. Unique Morse Code Words

International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: "a"maps to ".-", "b" maps to "-...", "c" maps to "-.-.", and so on.

For convenience, the full table for the 26 letters of the English alphabet is given below:

[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]

1	[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]

Now, given a list of words, each word can be written as a concatenation of the Morse code of each letter. For example, “cab” can be written as “-.-.-….-“, (which is the concatenation “-.-.” + “-…” + “.-“). We’ll call such a concatenation, the transformation of a word.

Return the number of different transformations among all words we have.

Example: 
Input: words = ["gin", "zen", "gig", "msg"] 
Output: 2 
Explanation: The transformation of each word is: 
"gin" -> "--...-." 
"zen" -> "--...-." 
"gig" -> "--...--." 
"msg" -> "--...--." 
There are 2 different transformations, "--...-." and "--...--.".

Example:

Input: words = ["gin", "zen", "gig", "msg"]

Output: 2

Explanation: The transformation of each word is:

"gin" -> "--...-."

"zen" -> "--...-."

"gig" -> "--...--."

"msg" -> "--...--."

There are 2 different transformations, "--...-." and "--...--.".

Note:

The length of words will be at most 100.
Each words[i] will have length in range [1, 12].
words[i] will only consist of lowercase letters.

let morseCode = ["a": "01", "b": "1000", "c": "1010", "d": "100", "e": "0", "f": "0010", "g": "110", "h": "0000", "i": "00", "j": "0111", "k": "101", "l": "0100", "m": "11", "n": "10", "o": "111", "p": "0110", "q": "1101", "r": "010", "s": "000", "t": "1", "u": "001", "v": "0001", "w": "011", "x": "1001", "y": "1011", "z": "1100"]
return Set(
        words.map { w in
            w.reduce("") { s, c in
                s + morseCode[String(c)]!
            }
        }).count

let morseCode = ["a": "01", "b": "1000", "c": "1010", "d": "100", "e": "0", "f": "0010", "g": "110", "h": "0000", "i": "00", "j": "0111", "k": "101", "l": "0100", "m": "11", "n": "10", "o": "111", "p": "0110", "q": "1101", "r": "010", "s": "000", "t": "1", "u": "001", "v": "0001", "w": "011", "x": "1001", "y": "1011", "z": "1100"]

return Set(

words.map { w in

w.reduce("") { s, c in

s + morseCode[String(c)]!

}

}).count

[swift] LeetCode 709. To Lower Case

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

Example 1:

Input: "Hello"
Output: "hello"

1 2	Input: "Hello" Output: "hello"

Example 2:

Input: "here"
Output: "here"

1 2	Input: "here" Output: "here"

Example 3:

Input: "LOVELY"
Output: "lovely"

1 2	Input: "LOVELY" Output: "lovely"

return str.lowercased()

1	return str.lowercased()

[swift] LeetCode 771. Jewels and Stones

You are 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:

Input: J = “aA”, S = “aAAbbbb”
Output: 3
Example 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.

return J.reduce(0) { sum, j in
            sum + S.filter({$0 == j}).count
        }

return J.reduce(0) { sum, j in

sum + S.filter({$0 == j}).count

}

[swift] LeetCode 695. Max Area of Island

Given a non-empty 2D array grid of 0’s and 1’s, an island is a group of 1’s (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.

Find the maximum area of an island in the given 2D array. (If there is no island, the maximum area is 0.)

Example 1:
[[0,0,1,0,0,0,0,1,0,0,0,0,0],
[0,0,0,0,0,0,0,1,1,1,0,0,0],
[0,1,1,0,1,0,0,0,0,0,0,0,0],
[0,1,0,0,1,1,0,0,1,0,1,0,0],
[0,1,0,0,1,1,0,0,1,1,1,0,0],
[0,0,0,0,0,0,0,0,0,0,1,0,0],
[0,0,0,0,0,0,0,1,1,1,0,0,0],
[0,0,0,0,0,0,0,1,1,0,0,0,0]]
Given the above grid, return 6. Note the answer is not 11, because the island must be connected 4-directionally.
Example 2:
[[0,0,0,0,0,0,0,0]]
Given the above grid, return 0.
Note: The length of each dimension in the given grid does not exceed 50.

func maxAreaOfIsland(_ grid: [[Int]]) -> Int {
    var i = 0, j = 0, v = 0
    var g = grid
    while i < grid.count {
        while j < grid[i].count {
            v = max(area(&g, i, j), v)
            j += 1
        }
        i += 1; j = 0
    }
    return v
}

private func area(_ g: inout [[Int]], _ i: Int, _ j: Int) -> Int {
    var v = 0
    if i < 0 || i >= g.count || j < 0 || j >= g[i].count {
        return 0
    }
    if g[i][j] == 1 {
        g[i][j] = 0; v = 1
        v += area(&g, i, j+1)
        v += area(&g, i+1, j)
        v += area(&g, i-1, j)
        v += area(&g, i, j-1)
    }
    return v
}

func maxAreaOfIsland(_ grid: [[Int]]) -> Int {

var i = 0, j = 0, v = 0

var g = grid

while i < grid.count {

while j < grid[i].count {

v = max(area(&g, i, j), v)

j += 1

}

i += 1; j = 0

}

return v

}

private func area(_ g: inout [[Int]], _ i: Int, _ j: Int) -> Int {

var v = 0

if i < 0 || i >= g.count || j < 0 || j >= g[i].count {

return 0

}

if g[i][j] == 1 {

g[i][j] = 0; v = 1

v += area(&g, i, j+1)

v += area(&g, i+1, j)

v += area(&g, i-1, j)

v += area(&g, i, j-1)

}

return v

}