C. Letters Cyclic Shift
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
You are given a non-empty string s consisting of lowercase English letters. You have to pick exactly
one non-empty substring of s and shift all its letters 'z' 
'y' 'x' 
'b' 'a' 'z'.
In other words, each character is replaced with the previous character of English alphabet and 'a' is replaced with 'z'.
What is the lexicographically minimum string that can be obtained from s by performing this shift exactly once?
Input
The only line of the input contains the string s (1 ≤ |s| ≤ 100 000) consisting of lowercase English letters.
Output
Print the lexicographically minimum string that can be obtained from s by shifting letters of exactly one non-empty substring.
Examples
input
codeforces
output
bncdenqbdr
input
abacaba
output
aaacaba
#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <algorithm>
#include <string>
using namespace std;
const int maxn=1e5;
char a[maxn+5];
char fun(char x)
{
char b=x;
if(x=='a')
b='z';
else
b--;
return b;
}
int main()
{
scanf("%s",a);
int len=strlen(a);
int l=len-1,r=len-1;
for(int i=0;i<len;i++)
{
if(l==len-1&&a[i]!='a')
l=i;
if(l!=len-1&&r==len-1&&a[i]=='a')
r=i-1;
}
for(int i=0;i<len;i++)
{
if(i<=r&&i>=l)
printf("%c",fun(a[i]));
else
printf("%c",a[i]);
}
printf("
");
return 0;
}