3174. Clear Digits

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3174. Clear Digits

Description

You are given a string s.

Your task is to remove all digits by doing this operation repeatedly:

  • Delete the first digit and the closest non-digit character to its left.

Return the resulting string after removing all digits.

Example 1:

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Input: s = "abc"

Output: "abc"

Explanation:

There is no digit in the string.

Example 2:

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Input: s = "cb34"

Output: ""

Explanation:

First, we apply the operation on `s[2]`, and `s` becomes `"c4"`.

Then we apply the operation on `s[1]`, and `s` becomes `""`.

Constraints:

  • 1 <= s.length <= 100
  • s consists only of lowercase English letters and digits.
  • The input is generated such that it is possible to delete all digits.

Hints/Notes

  • Biweekly Contest 132

Solution

Language: C++

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class Solution {
public:
    string clearDigits(string s) {
        stack<char> str;
        for (char c : s) {
            if (c >= '0' && c <= '9') {
                str.pop();
            } else {
                str.push(c);
            }
        }
        string res;
        while (!str.empty()) {
            res.push_back(str.top());
            str.pop();
        }
        reverse(res.begin(), res.end());
        return res;
    }
};