Answer:
// CPP program to Convert characters Â
// of a string to opposite case Â
#include<iostream> Â
using namespace std; Â
// Function to convert characters Â
// of a string to opposite case Â
void convertOpposite(string &str) Â
{ Â
int ln = str.length(); Â
Â
// Conversion according to ASCII values Â
for (int i=0; i<ln; i++) Â
{ Â
 if (str[i]>='a' && str[i]<='z') Â
 //Convert lowercase to uppercase Â
 str[i] = str[i] - 32; Â
 else if(str[i]>='A' && str[i]<='Z') Â
 //Convert uppercase to lowercase Â
 str[i] = str[i] + 32; Â
} Â
} Â
// Driver function Â
int main() Â
{ Â
string str = "GeEkSfOrGeEkS"; Â
Â
// Calling the Function Â
convertOpposite(str); Â
Â
cout << str; Â
return 0; Â
} Â
Explanation: