32 lines
738 B
C++
32 lines
738 B
C++
#include <vector>
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#include <functional>
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#include <cctype>
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/**
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* 784. Letter Case Permutation
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*
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* Given a string s, you can transform every letter individually to be lowercase or uppercase to create another string.
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* Return a list of all possible strings we could create. Return the output in any order.
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*/
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class Solution {
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public:
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std::vector<std::string> letterCasePermutation(std::string& s) {
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std::vector<std::string> ret;
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std::function<void(int)> f = [&](int pos) {
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if (pos >= s.length()) {
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ret.push_back(s);
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} else if (std::isalpha(s[pos])) {
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s[pos] = std::tolower(s[pos]);
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f(1 + pos);
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s[pos] = std::toupper(s[pos]);
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f(1 + pos);
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} else {
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f(1 + pos);
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}
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};
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f(0);
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return ret;
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}
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};
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