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-rw-r--r-- | min_num_swap_string_balance.c | 32 | ||||
-rw-r--r-- | min_num_swap_string_balance.py | 33 |
2 files changed, 65 insertions, 0 deletions
diff --git a/min_num_swap_string_balance.c b/min_num_swap_string_balance.c new file mode 100644 index 0000000..4706fbe --- /dev/null +++ b/min_num_swap_string_balance.c @@ -0,0 +1,32 @@ +// 1963. Minimum Number of Swaps to Make the String Balanced +#include "leetcode.h" + +/* + * you are given a 0-indexed string 's' of even length 'n'. the string consists + * of exactly 'n / 2' opening and closing square brackets. a string is called + * balanced if and only if it is empty string, it can be written as 'AB' where + * both 'A' and 'B' are balanced strings, or it can be written as '[C]' where + * 'C' is a balanced string. you may swap the brackets at any two indices any + * number of times. return the minimum number of swaps to make 's' balanced + */ + +int minSwaps(char *s) { + int bal = 0, ans = 0, i = 0; + while (s[i]) { + if (s[i] == '[') + bal--; + else if (s[i] == ']') + bal++; + if (bal > ans) + ans = bal; + ++i; + } + return (ans + 1) / 2; +} + +int main() { + char *s1 = "][][", *s2 = "]]][[[", *s3 = "[]"; + printf("%d\n", minSwaps(s1)); // expect: 1 + printf("%d\n", minSwaps(s2)); // expect: 2 + printf("%d\n", minSwaps(s3)); // expect: 0 +} diff --git a/min_num_swap_string_balance.py b/min_num_swap_string_balance.py new file mode 100644 index 0000000..d7114f8 --- /dev/null +++ b/min_num_swap_string_balance.py @@ -0,0 +1,33 @@ +# 1963. Minimum Number of Swaps to Make the String Balanced + +""" +you are given a 0-indexed string 's' of even length 'n'. the string consists +of exactly 'n / 2' opening and closing square brackets. a string is called +balanced if and only if it is empty string, it can be written as 'AB' where +both 'A' and 'B' are balanced strings, or it can be written as '[C]' where +'C' is a balanced string. you may swap the brackets at any two indices any +number of times. return the minimum number of swaps to make 's' balanced +""" + + +class Solution(object): + def minSwaps(self, s): + """ + :type s: str + :rtype: int + """ + bal, ans = 0, 0 + for c in s: + if c == "[": + bal += 1 + else: + bal -= 1 + ans = min(ans, bal) + return (-ans + 1) // 2 + + +if __name__ == "__main__": + obj = Solution() + print(obj.minSwaps(s="][][")) + print(obj.minSwaps(s="]]][[[")) + print(obj.minSwaps(s="[]")) |