Sponsored
Sponsored
This approach involves using dynamic programming with memoization to find the minimum number of turns needed to print the string. The idea is to define a recursive function that prints a substring from index i to index j, using memoization to avoid unnecessary repeated calculations.
Time Complexity: O(n^3), Space Complexity: O(n^2)
1using System;
2
3public class Solution {
4 public int StrangePrinter(string s) {
5 int n = s.Length;
6 int[,] dp = new int[n, n];
7 for (int len = 1; len <= n; ++len) {
8 for (int i = 0; i + len <= n; ++i) {
9 int j = i + len - 1;
10 dp[i, j] = (i == j) ? 1 : dp[i + 1, j] + 1;
11 for (int k = i + 1; k <= j; ++k) {
12 if (s[k] == s[i]) {
13 dp[i, j] = Math.Min(dp[i, j], dp[i, k - 1] + (k + 1 <= j ? dp[k + 1, j] : 0));
14 }
15 }
16 }
17 }
18 return dp[0, n - 1];
19 }
20 public static void Main(string[] args) {
21 Solution solution = new Solution();
22 Console.WriteLine(solution.StrangePrinter("aba"));
23 }
24}This C# approach similarly leverages dynamic programming, where a 2D array dp employs nested loops and decision-making rules on segments from i to j. The minimum operations are found through comparisons among characters and spans of identical characters.
This approach uses a greedy strategy to minimize the number of character segments that need to be printed. Instead of forming a full dp matrix, it strategizes the printing operations based on visible segments of similar characters, exploiting shared coverage.
Time Complexity: O(n^3), Space Complexity: O(n^2). This primarily stems from recursive splitting subproblems by string breakdown.
1class Solution:
2 def strangePrinter(self, s: str) ->
This optimized greedy Python solution leverages a streamlined version of the string by compressing repeated characters. It utilizes memoization within a divided recursive structure. Segments are collapsed as the helper ranges over valid substrings, aiming for spaced repetition minimization.