运行 ID: 122223

Main.cc: In function ‘int main()’:
Main.cc:9:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i= 'a'&&s[i-1] <= 'z'&&s[i+1]>='a'&&s[i+1]<='z'||s[i+1] >= '0'&&s[i+1] <= '9'&&s[i-1]>='0'&&s[i-1]<='9')){