时间复杂度(O( n))
class Solution {
public:
string toLowerCase(string str) {
for(int i=0;i<str.size();++i) if(str[i]<='Z' && str[i]>='A') str[i]=str[i]-'A'+'a';
return str;
}
};
时间复杂度(O( n))
class Solution {
public:
string toLowerCase(string str) {
for(int i=0;i<str.size();++i) if(str[i]<='Z' && str[i]>='A') str[i]=str[i]-'A'+'a';
return str;
}
};