# include<iostream> # include<cmath>//abs的头文件 using namespace std; int main(){ //'A'->65,'Z'->90 //'a'->97,'z'->122 char c;//存录入的字符 cin>>c; if(c>=65){ if(c<=90){ c=c+32;//将大写转成小写 } else{ c=c-32; } } cout<<c<<endl; return 0; }