Total Characters in String After Transformations I
You receive a string s and an integer t , representing the number of transformations to perform. In one transformation , every character in s is replaced according to the following rules:
-
If the character is
'z', replace it with the text"ab". -
Otherwise, replace it with the next character in the alphabet. For example,
'a'is replaced with'b','b'is replaced with'c', and so on.
Produce the length of the resulting string after exactly t transformations.
Since the answer may be very large, produce it modulo 10^9+ 7 .
Input: s = "abcyy", t = 2
Output: 7
Explanation:
-
First Transformation (t = 1):
-
'a'becomes'b' -
'b'becomes'c' -
'c'becomes'd' -
'y'becomes'z' -
'y'becomes'z' -
String after the first transformation:
"bcdzz"
-
-
Second Transformation (t = 2):
-
'b'becomes'c' -
'c'becomes'd' -
'd'becomes'e' -
'z'becomes"ab" -
'z'becomes"ab" -
String after the second transformation:
"cdeabab"
-
-
Final Length of the string: The string is
"cdeabab", which has 7 characters.
Input: s = "azbk", t = 1
Output: 5
Explanation:
-
First Transformation (t = 1):
-
'a'becomes'b' -
'z'becomes"ab" -
'b'becomes'c' -
'k'becomes'l' -
String after the first transformation:
"babcl"
-
-
Final Length of the string: The string is
"babcl", which has 5 characters.
Constraints
1 <= s.length <= 10^5sconsists only of lowercase English letters.1 <= t <= 10^5
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