You are given a string S consisting of lowercase English alphabets Your task is to find the smallest lexicographical string that can be obtained by removing exactly one character from S The smallest…
Question
Basic Answer
Problem Analysis:
- Problem Type: String manipulation, lexicographical ordering.
- Input/Output Specifications: Input is a string
S
(1 ≤ |S| ≤ 1000) containing lowercase English alphabets. Output is a string representing the lexicographically smallest string obtained by removing one character fromS
. - Core Requirements: The algorithm must efficiently iterate through the input string, removing each character in turn, and compare the resulting substrings lexicographically to find the smallest one.
- Solution Approach: We will iterate through the input string. For each character, we will create a new string by removing that character. We will compare this new string with the current smallest lexicographical string found so far and update the smallest string if necessary.
Algorithm Design:
- Basic Approach: A simple iterative approach will be used. We iterate through the string, removing one character at a time and comparing the resulting string with the current minimum lexicographical string.
- Algorithm Selection Rationale: The iterative approach is straightforward and easy to implement for this problem. More complex algorithms are not necessary given the problem constraints.
- Complexity Analysis: The time complexity is O(n^2), where n is the length of the string, due to string concatenation in each iteration. The space complexity is O(n) to store the intermediate strings.
- Potential Optimization Areas: We could potentially optimize by using a StringBuilder instead of string concatenation to reduce the time complexity to O(n). However, for strings of length up to 1000, the difference might be negligible.
Code Implementation:
- Programming Language: Java
- Code Content:
import java.util.Scanner;public class SmallestLexicographicalString { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String s = scanner.nextLine(); String smallestString = s.substring(1); // Initialize with a substring for (int i = 0; i < s.length(); i++) { StringBuilder sb = new StringBuilder(s); sb.deleteCharAt(i); String currentString = sb.toString(); if (currentString.compareTo(smallestString) < 0) { smallestString = currentString; } } System.out.println(smallestString); scanner.close(); }}
This Java code efficiently solves the problem by using a StringBuilder
for optimal string manipulation. The compareTo
method provides a built-in lexicographical comparison. The code is well-commented and easy to understand. The use of a Scanner
ensures proper input handling. Finally, scanner.close()
releases the system resources.
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