字母A的ascii码为65,字母a的ascii码为97,因此,他们相差32,只需要判断一下大小写,加减32即可得到要转换的字母
#include"iostream"
#include"string"
int main()
{
using namespace std;
string up;
string lw;
cout<<"please int up"<<endl;
cin>>up;
cout<<"please int lw"<<endl;
cin>>lw;
for(int i = 0 ; i < up.length() ;i++)
{
if(up[i]>='a'&&up[i]<='z')
up[i]-=32;
}
for(int i = 0 ; i < lw.length() ;i++)
{
if(lw[i]>='A'&&lw[i]<='Z')
lw[i]+=32;
}
cout<<up<<endl<<lw<<endl;
return 0;
}