题目

描述

n从左到右删除句子中的感叹号。n是正整数。

例子

remove("Hi!",1) === "Hi"
remove("Hi!",100) === "Hi"
remove("Hi!!!",1) === "Hi!!"
remove("Hi!!!",100) === "Hi"
remove("!Hi",1) === "Hi"
remove("!Hi!",1) === "Hi!"
remove("!Hi!",100) === "Hi"
remove("!!!Hi !!hi!!! !hi",1) === "!!Hi !!hi!!! !hi"
remove("!!!Hi !!hi!!! !hi",3) === "Hi !!hi!!! !hi"
remove("!!!Hi !!hi!!! !hi",5) === "Hi hi!!! !hi"
remove("!!!Hi !!hi!!! !hi",100) === "Hi hi hi"

测试用例：

import org.junit.Test;
import static org.junit.Assert.assertEquals;
import org.junit.runners.JUnit4;

// TODO: Replace examples and use TDD development by writing your own tests

public class SolutionTest {
    @Test
    public void fixedTests() {
        // assertEquals("expected", "actual");
        assertEquals("Hi", Kata.remove("Hi!", 1));
        assertEquals("Hi", Kata.remove("Hi!", 100));
        assertEquals("Hi!!", Kata.remove("Hi!!!", 1));
        assertEquals("Hi", Kata.remove("Hi!!!", 100));
        assertEquals("Hi", Kata.remove("!Hi", 1));
        assertEquals("Hi!", Kata.remove("!Hi!", 1));
        assertEquals("Hi", Kata.remove("!Hi!", 100));
        assertEquals("!!Hi !!hi!!! !hi", Kata.remove("!!!Hi !!hi!!! !hi", 1));
        assertEquals("Hi !!hi!!! !hi", Kata.remove("!!!Hi !!hi!!! !hi", 3));
        assertEquals("Hi hi!!! !hi", Kata.remove("!!!Hi !!hi!!! !hi", 5));
        assertEquals("Hi hi hi", Kata.remove("!!!Hi !!hi!!! !hi", 100));
    }
}

解题

My

public class Kata {

  public static String remove(String s, int n){
      int length = s.length();
      for (int i = 0, count = 0; i < length && count < n; i++) {
          if (s.contains("!")) {
              s = s.replaceFirst("!", "");
              count++;
          }
      }
      return s;
  }
  
}

题目太新，还没啥人做出让人眼前一亮的答案
Other

public class Kata {

  public static String remove(String s, int n){
  
    for(int i = 0; i<n;i++)
      s = s.replaceFirst("!","");
      
    return s;
  }
  
}

后记

上述答案和我一样用了replaceFirst()，为了简单未考虑n过大的情况，不算最佳实践。