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-rw-r--r--find_longest_awesome_substr.c29
-rw-r--r--find_longest_awesome_substr.py31
2 files changed, 60 insertions, 0 deletions
diff --git a/find_longest_awesome_substr.c b/find_longest_awesome_substr.c
new file mode 100644
index 0000000..6e4462a
--- /dev/null
+++ b/find_longest_awesome_substr.c
@@ -0,0 +1,29 @@
+// 1542. Find Longest Awesome Substring
+#include "leetcode.h"
+
+/*
+ * you are given a string 's'. an awesome substring is a non-empty substring of
+ * 's' such that we can make any number of swaps in order to make it a
+ * palindrome. return the length of the maximum length awesome substring of 's'.
+ */
+
+int longestAwesome(char *s) {
+ int n = strlen(s), ans = 0, mask = 0, dp[1024];
+ memset(dp, n, sizeof(dp));
+ dp[0] = -1;
+ for (int i = 0; i < n; ++i) {
+ mask ^= 1 << (s[i] - '0');
+ ans = fmax(ans, i - dp[mask]);
+ for (int j = 0; j <= 9; ++j)
+ ans = fmax(ans, i - dp[mask ^ (1 << j)]);
+ dp[mask] = fmin(dp[mask], i);
+ }
+ return ans;
+}
+
+int main() {
+ char *s1 = "3242415", *s2 = "12345678", *s3 = "213123";
+ printf("%d\n", longestAwesome(s1)); // expect: 5
+ printf("%d\n", longestAwesome(s2)); // expect: 1
+ printf("%d\n", longestAwesome(s3)); // expect: 6
+}
diff --git a/find_longest_awesome_substr.py b/find_longest_awesome_substr.py
new file mode 100644
index 0000000..d4113d6
--- /dev/null
+++ b/find_longest_awesome_substr.py
@@ -0,0 +1,31 @@
+# 1542. Find Longest Awesome Substring
+
+"""
+you are given a string 's'. an awesome substring is a non-empty substring of
+'s' such that we can make any number of swaps in order to make it a
+palindrome. return the length of the maximum length awesome substring of 's'.
+"""
+
+
+class Solution(object):
+ def longestAwesome(self, s):
+ """
+ :type s: str
+ :rtype: int
+ """
+ ans, mask = 0, 0
+ dp = [-1] + [len(s)] * 1023
+ for i in range(len(s)):
+ mask ^= 1 << (ord(s[i]) - 48)
+ for j in range(11):
+ check = 1023 & (mask ^ (1 << j))
+ ans = max(ans, i - dp[check])
+ dp[mask] = min(dp[mask], i)
+ return ans
+
+
+if __name__ == "__main__":
+ obj = Solution()
+ print(obj.longestAwesome(s="3242415"))
+ print(obj.longestAwesome(s="12345678"))
+ print(obj.longestAwesome(s="213123"))