第十周算法提高9-2文本加密

#include<iostream> 
using namespace std;
int main(){
	char arr[55];
	int i=0;
	cin>>arr;
	while(arr[i]!='\0'){
		if(arr[i]=='A')arr[i]='B';
		else if(arr[i]=='A')arr[i]='B';
		else if(arr[i]=='B')arr[i]='C';
		else if(arr[i]=='C')arr[i]='D';
		else if(arr[i]=='D')arr[i]='E';
		else if(arr[i]=='E')arr[i]='F';
		else if(arr[i]=='F')arr[i]='G';
		else if(arr[i]=='G')arr[i]='H';
		else if(arr[i]=='H')arr[i]='I';
		else if(arr[i]=='I')arr[i]='J';
		else if(arr[i]=='J')arr[i]='K';
		else if(arr[i]=='K')arr[i]='L';
		else if(arr[i]=='L')arr[i]='M';
		else if(arr[i]=='M')arr[i]='N';
		else if(arr[i]=='N')arr[i]='O';
		else if(arr[i]=='O')arr[i]='P';
		else if(arr[i]=='P')arr[i]='Q';
		else if(arr[i]=='Q')arr[i]='R';
		else if(arr[i]=='R')arr[i]='S';
		else if(arr[i]=='S')arr[i]='T';
		else if(arr[i]=='T')arr[i]='U';
		else if(arr[i]=='U')arr[i]='V';
		else if(arr[i]=='V')arr[i]='W';
		else if(arr[i]=='W')arr[i]='X';
		else if(arr[i]=='X')arr[i]='Y';
		else if(arr[i]=='Y')arr[i]='Z';
		else if(arr[i]=='Z')arr[i]='a';
		else if(arr[i]=='a')arr[i]='b';
		else if(arr[i]=='b')arr[i]='c';
		else if(arr[i]=='c')arr[i]='d';
		else if(arr[i]=='d')arr[i]='e';		
		else if(arr[i]=='e')arr[i]='f';
		else if(arr[i]=='f')arr[i]='g';
		else if(arr[i]=='g')arr[i]='h';
		else if(arr[i]=='h')arr[i]='i';
		else if(arr[i]=='i')arr[i]='j';
		else if(arr[i]=='j')arr[i]='k';
		else if(arr[i]=='k')arr[i]='l';
		else if(arr[i]=='l')arr[i]='m';
		else if(arr[i]=='m')arr[i]='n';
		else if(arr[i]=='n')arr[i]='o';
		else if(arr[i]=='o')arr[i]='p';
		else if(arr[i]=='p')arr[i]='q';
		else if(arr[i]=='q')arr[i]='r';
		else if(arr[i]=='r')arr[i]='s';
		else if(arr[i]=='s')arr[i]='t';
		else if(arr[i]=='t')arr[i]='u';
		else if(arr[i]=='u')arr[i]='v';
		else if(arr[i]=='v')arr[i]='w';
		else if(arr[i]=='w')arr[i]='x';
		else if(arr[i]=='x')arr[i]='y';
		else if(arr[i]=='y')arr[i]='z';
		else if(arr[i]=='z')arr[i]='A';
		
		i++;
	}
	cout<<arr;
	return 0;
}