LeetCode //C - 1221. Split a String in Balanced Strings

1221. Split a String in Balanced Strings

Balanced strings are those that have an equal quantity of 'L' and 'R' characters.

Given a balanced string s, split it into some number of substrings such that:

• Each substring is balanced.

Return the maximum number of balanced strings you can obtain.

Example 1:

Input: s = "RLRRLLRLRL"

Output: 4

Explanation: s can be split into "RL", "RRLL", "RL", "RL", each substring contains same number of 'L' and 'R'.

Example 2:

Input: s = "RLRRRLLRLL"

Output: 2

Explanation: s can be split into "RL", "RRRLLRLL", each substring contains same number of 'L' and 'R'.

Note that s cannot be split into "RL", "RR", "RL", "LR", "LL", because the 2nd and 5th substrings are not balanced.

Example 3:

Input: s = "LLLLRRRR"

Output: 1

Explanation: s can be split into "LLLLRRRR".

Constraints:

• 2 <= s.length <= 1000
• si is either 'L' or 'R'.
• s is a balanced string.

From: LeetCode

Link: 1221. Split a String in Balanced Strings

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Solution:

Ideas:

use a counter. Add +1 for R, -1 for L. Every time counter becomes 0, we found one balanced substring.

Code:

int balancedStringSplit(char* s) {
    int balance = 0;
    int count = 0;

    for (int i = 0; s[i] != '\0'; i++) {
        if (s[i] == 'R') {
            balance++;
        } else {
            balance--;
        }

        if (balance == 0) {
            count++;
        }
    }

    return count;
}