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Diffstat (limited to 'longest_binary_subseq_leq_k.c')
-rw-r--r-- | longest_binary_subseq_leq_k.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/longest_binary_subseq_leq_k.c b/longest_binary_subseq_leq_k.c new file mode 100644 index 0000000..7920e7d --- /dev/null +++ b/longest_binary_subseq_leq_k.c @@ -0,0 +1,30 @@ +// 2311. Longest Binary Subsequence Less Than or Equal to K +#include "leetcode.h" + +/* + * you are given a binary string 's' and a positive integer 'k'. return the + * length of the longest subsequence of 's' that makes up a binary number less + * than or equal to 'k'. note the subsequence can contain leading zeros, the + * empty string is considered to be equal to 0, and a subsequence is a string + * that can be derived from another string by deleting some or no characters + * without changing the order of the remaining characters. + */ + +int longestSubsequence(char *s, int k) { + int ans = 0, cost = 1, n = strlen(s); + for (int i = n - 1; i >= 0; --i) { + if (s[i] == '0' || cost <= k) { + k -= cost * (s[i] - '0'); + ans++; + } + if (cost <= k) + cost *= 2; + } + return ans; +} + +int main() { + char *s1 = "1001010", *s2 = "00101001"; + printf("%d\n", longestSubsequence(s1, 5)); // expect: 5 + printf("%d\n", longestSubsequence(s2, 1)); // expect: 6 +} |