README_EN.md

1933. Check if String Is Decomposable Into Value-Equal Substrings

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Description

A value-equal string is a string where all characters are the same.

• For example, "1111" and "33" are value-equal strings.
• In contrast, "123" is not a value-equal string.

Given a digit string s, decompose the string into some number of consecutive value-equal substrings where exactly one substring has a length of 2 and the remaining substrings have a length of 3.

Return true if you can decompose s according to the above rules. Otherwise, return false.

A substring is a contiguous sequence of characters in a string.

 

Example 1:

Input: s = "000111000"
Output: false
Explanation: s cannot be decomposed according to the rules because ["000", "111", "000"] does not have a substring of length 2.

Example 2:

Input: s = "00011111222"
Output: true
Explanation: s can be decomposed into ["000", "111", "11", "222"].

Example 3:

Input: s = "011100022233"
Output: false
Explanation: s cannot be decomposed according to the rules because of the first '0'.

 

Constraints:

• 1 <= s.length <= 1000
• s consists of only digits '0' through '9'.

Solutions

Python3

class Solution:
    def isDecomposable(self, s: str) -> bool:
        i, n = 0, len(s)
        cnt2 = 0
        while i < n:
            j = i
            while j < n and s[j] == s[i]:
                j += 1
            if (j - i) % 3 == 1:
                return False
            cnt2 += (j - i) % 3 == 2
            if cnt2 > 1:
                return False
            i = j
        return cnt2 == 1

Java

class Solution {
    public boolean isDecomposable(String s) {
        int i = 0, n = s.length();
        int cnt2 = 0;
        while (i < n) {
            int j = i;
            while (j < n && s.charAt(j) == s.charAt(i)) {
                ++j;
            }
            if ((j - i) % 3 == 1) {
                return false;
            }
            if ((j - i) % 3 == 2 && ++cnt2 > 1) {
                return false;
            }
            i = j;
        }
        return cnt2 == 1;
    }
}

C++

class Solution {
public:
    bool isDecomposable(string s) {
        int i = 0, n = s.size();
        int cnt2 = 0;
        while (i < n) {
            int j = i;
            while (j < n && s[j] == s[i]) ++j;
            if ((j - i) % 3 == 1) return false;
            if ((j - i) % 3 == 2 && ++cnt2 > 1) return false;
            i = j;
        }
        return cnt2 == 1;
    }
};

Go

func isDecomposable(s string) bool {
	i, n := 0, len(s)
	cnt2 := 0
	for i < n {
		j := i
		for j < n && s[j] == s[i] {
			j++
		}
		if (j-i)%3 == 1 {
			return false
		}
		if (j-i)%3 == 2 {
			cnt2++
			if cnt2 > 1 {
				return false
			}
		}
		i = j
	}
	return cnt2 == 1
}

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