zoukankan      html  css  js  c++  java
  • [Swift]LeetCode664. 奇怪的打印机 | Strange Printer

    ★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★
    ➤微信公众号:山青咏芝(shanqingyongzhi)
    ➤博客园地址:山青咏芝(https://www.cnblogs.com/strengthen/
    ➤GitHub地址:https://github.com/strengthen/LeetCode
    ➤原文地址:https://www.cnblogs.com/strengthen/p/10492196.html 
    ➤如果链接不是山青咏芝的博客园地址,则可能是爬取作者的文章。
    ➤原文已修改更新!强烈建议点击原文地址阅读!支持作者!支持原创!
    ★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★

    There is a strange printer with the following two special requirements:

    1. The printer can only print a sequence of the same character each time.
    2. At each turn, the printer can print new characters starting from and ending at any places, and will cover the original existing characters. 

    Given a string consists of lower English letters only, your job is to count the minimum number of turns the printer needed in order to print it.

    Example 1:

    Input: "aaabbb"
    Output: 2
    Explanation: Print "aaa" first and then print "bbb". 

    Example 2:

    Input: "aba"
    Output: 2
    Explanation: Print "aaa" first and then print "b" from the second place of the string, which will cover the existing character 'a'.

    Hint: Length of the given string will not exceed 100.


    有台奇怪的打印机有以下两个特殊要求:

    1. 打印机每次只能打印同一个字符序列。
    2. 每次可以在任意起始和结束位置打印新字符,并且会覆盖掉原来已有的字符。

    给定一个只包含小写英文字母的字符串,你的任务是计算这个打印机打印它需要的最少次数。

    示例 1:

    输入: "aaabbb"
    输出: 2
    解释: 首先打印 "aaa" 然后打印 "bbb"。
    

    示例 2:

    输入: "aba"
    输出: 2
    解释: 首先打印 "aaa" 然后在第二个位置打印 "b" 覆盖掉原来的字符 'a'。

    提示: 输入字符串的长度不会超过 100。


    116ms

     1 class Solution {
     2     func strangePrinter(_ s: String) -> Int {
     3         var c = [Character]()
     4         var pre : Character = " "
     5         for (_, char) in s.enumerated() {
     6             if char != pre {
     7                 c.append(char)
     8                 pre = char
     9             }
    10         }
    11         var l = [[Int]](repeating:[Int](repeating: 0, count:c.count) , count:c.count)
    12         return turn(c, 0, c.count - 1, &l)
    13     }
    14     
    15     func turn(_ c: [Character], _ i: Int, _ j: Int, _ l: inout [[Int]]) -> Int {
    16         if i > j {
    17             return 0
    18         }
    19         if l[i][j] > 0 {
    20             return l[i][j]
    21         }
    22         var ans = turn(c, i, j-1, &l) + 1
    23         for k in i ..< j {
    24             if c[k] == c[j] {
    25                 ans = min(ans, turn(c, i, k, &l) + turn(c, k+1, j-1, &l))
    26             }
    27         }
    28         l[i][j] = ans
    29         return ans
    30     }
    31 }

    Runtime: 196 ms
    Memory Usage: 19.9 MB
     1 class Solution {
     2     func strangePrinter(_ s: String) -> Int {
     3         if s.isEmpty {return 0}
     4         var arr:[Character] = Array(s)
     5         var n:Int = s.count
     6         var dp:[[Int]] = [[Int]](repeating:[Int](repeating:0,count:n),count:n)
     7         for i in (0...(n - 1)).reversed()
     8         {
     9             if(n < i) {continue}
    10             for j in i..<n
    11             {
    12                 dp[i][j] = (i == j) ? 1 : (1 + dp[i + 1][j])
    13                 if(j < i + 1) {continue}
    14                 for k in (i + 1)...j
    15                 {
    16                     if arr[k] == arr[i]
    17                     {
    18                         dp[i][j] = min(dp[i][j], dp[i + 1][k - 1] + dp[k][j])
    19                     }
    20                 }
    21             }
    22         }
    23         return (n == 0) ? 0 : dp[0][n - 1]
    24     }
    25 }
  • 相关阅读:
    关于链表
    Linux操作系统(3):crond 任务调度
    高速信号的确定
    python 多线程 QTimer定时自动重复执行某个函数,QSS应用
    使用qtawesome这个第三方库来实现按钮中的Font Awesome字体图标的显示,叠层显示,多窗口显示,窗口禁止缩放,最大化,tap widget使用,按键颜色,建立相关文件路径,点击主窗口退出程序
    IP,子网掩码,网关,DNS的关系解析
    ZLAN6042使用源码(modbus-tcp)
    模块cv2的用法
    python(如何将数据写入本地txt文本文件)
    你猜我猜的经验-电源
  • 原文地址:https://www.cnblogs.com/strengthen/p/10492196.html
Copyright © 2011-2022 走看看