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-rw-r--r-- | total_char_str_transform1.c | 40 | ||||
-rw-r--r-- | total_char_str_transform1.py | 31 |
2 files changed, 71 insertions, 0 deletions
diff --git a/total_char_str_transform1.c b/total_char_str_transform1.c new file mode 100644 index 0000000..50ee3a9 --- /dev/null +++ b/total_char_str_transform1.c @@ -0,0 +1,40 @@ +// 3335. Total Characters in String After Transformations I +#include "leetcode.h" + +/* + * you are given 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 string 'ab'. otherwise, replace it with the next character in the + * alphabet. return the length of the resulting string after exactly 't' + * transformations. since the answer may be very large, return it modulo 10^9 + * + 7. + */ + +int lengthAfterTransformations(char *s, int t) { + const int mod = 1e9 + 7; + int cnt[26] = {0}, n = strlen(s); + for (int i = 0; i < n; i++) + cnt[s[i] - 'a']++; + for (int i = 0; i < t; i++) { + int tmp[26] = {0}; + for (int j = 0; j < 26; j++) { + if (j == 25) { + tmp[0] = (tmp[0] + cnt[j]) % mod; + tmp[1] = (tmp[1] + cnt[j]) % mod; + } else + tmp[j + 1] = (tmp[j + 1] + cnt[j]) % mod; + } + memcpy(cnt, tmp, sizeof(cnt)); + } + int ans = 0; + for (int i = 0; i < 26; i++) + ans = (ans + cnt[i]) % mod; + return ans; +} + +int main() { + char *s1 = "abcyy", *s2 = "azbk"; + printf("%d\n", lengthAfterTransformations(s1, 2)); // expect: 7 + printf("%d\n", lengthAfterTransformations(s2, 1)); // expect: 5 +} diff --git a/total_char_str_transform1.py b/total_char_str_transform1.py new file mode 100644 index 0000000..d4b2471 --- /dev/null +++ b/total_char_str_transform1.py @@ -0,0 +1,31 @@ +# 3335. Total Characters in String After Transformations I + +""" +you are given 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 string 'ab'. otherwise, replace it with the next character in the +alphabet. return the length of the resulting string after exactly 't' +transformations. since the answer may be very large, return it modulo 10^9 ++ 7. +""" + + +class Solution(object): + def lengthAfterTransformations(self, s, t): + """ + :type s: str + :type t: int + :rtype: int + """ + mod = 10**9 + 7 + dp = [1] * 26 + [0] * 100100 + for i in range(26, 100100): + dp[i] = (dp[i - 26] + dp[i - 26 + 1]) % mod + return sum(dp[ord(c) - ord("a") + t] for c in s) % mod + + +if __name__ == "__main__": + obj = Solution() + print(obj.lengthAfterTransformations(s="abcyy", t=2)) + print(obj.lengthAfterTransformations(s="azbk", t=1)) |