update

1 files changed, 34 insertions, 0 deletions

diff --git a/Computer_Science/leetcode/5-longest_palindromic_substring.c b/Computer_Science/leetcode/5-longest_palindromic_substring.c
new file mode 100644
index 0000000..ee65b8e
--- /dev/null
+++ b/Computer_Science/leetcode/5-longest_palindromic_substring.c
@@ -0,0 +1,34 @@
+void extend(char *s, int len, int i, int j, int *lo, int *hi)
+{
+	while(i >= 0 && i < len && s[i] == s[j]) {
+		i--;
+		j++;
+	}
+
+	if(j - i > *hi - *lo) {
+		*lo = i;
+		*hi = j;
+	}
+}
+
+char* longestPalindrome(char* s) {
+	int *lo, *hi;
+	int len = strlen(s);
+
+	lo = malloc(sizeof(int));
+	hi = malloc(sizeof(int));
+
+	*lo = *hi = 0;
+	if(len < 2)
+		return s;
+
+	for(int i = 0; i < len - 1; i++) {
+		extend(s, len, i, i, lo, hi);
+		extend(s, len, i, i + 1, lo, hi);
+	}
+
+	*(s + (*hi)) = '\0';
+	return s + *lo + 1;
+}
+
+