Question

709. To Lower Case

中文文档

Description

Given a string s, return _the string after replacing every uppercase letter with the same lowercase letter_.

 

Example 1:

Input: s = "Hello"
Output: "hello"

Example 2:

Input: s = "here"
Output: "here"

Example 3:

Input: s = "LOVELY"
Output: "lovely"

 

Constraints:

• 1 <= s.length <= 100
• s consists of printable ASCII characters.

Solutions

Solution 1

class Solution:
  def toLowerCase(self, s: str) -> str:
    return "".join([chr(ord(c) | 32) if c.isupper() else c for c in s])

class Solution {
  public String toLowerCase(String s) {
    char[] cs = s.toCharArray();
    for (int i = 0; i < cs.length; ++i) {
      if (cs[i] >= 'A' && cs[i] <= 'Z') {
        cs[i] |= 32;
      }
    }
    return String.valueOf(cs);
  }
}

class Solution {
public:
  string toLowerCase(string s) {
    for (char& c : s) {
      if (c >= 'A' && c <= 'Z') {
        c |= 32;
      }
    }
    return s;
  }
};

func toLowerCase(s string) string {
  cs := []byte(s)
  for i, c := range cs {
    if c >= 'A' && c <= 'Z' {
      cs[i] |= 32
    }
  }
  return string(cs)
}

function toLowerCase(s: string): string {
  return s.toLowerCase();
}

impl Solution {
  pub fn to_lower_case(s: String) -> String {
    s.to_ascii_lowercase()
  }
}

char* toLowerCase(char* s) {
  int n = strlen(s);
  for (int i = 0; i < n; i++) {
    if (s[i] >= 'A' && s[i] <= 'Z') {
      s[i] |= 32;
    }
  }
  return s;
}

Solution 2

function toLowerCase(s: string): string {
  return [...s].map(c => String.fromCharCode(c.charCodeAt(0) | 32)).join('');
}

impl Solution {
  pub fn to_lower_case(s: String) -> String {
    s.as_bytes()
      .iter()
      .map(|&c| char::from(if c >= b'A' && c <= b'Z' { c | 32 } else { c }))
      .collect()
  }
}