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| author | crupest <crupest@outlook.com> | 2020-08-17 20:49:29 +0800 |
|---|---|---|
| committer | crupest <crupest@outlook.com> | 2020-08-17 20:49:29 +0800 |
| commit | c69f5d2153b880762931a29c5eec8188e2aa25ed (patch) | |
| tree | 7d8fce442ce9cff2c1f5eb622afe93337c02df34 /cpp/20.cpp | |
| parent | e027c0c482539aa0e272083f056d2d053746c390 (diff) | |
| download | solutions-c69f5d2153b880762931a29c5eec8188e2aa25ed.tar.gz solutions-c69f5d2153b880762931a29c5eec8188e2aa25ed.tar.bz2 solutions-c69f5d2153b880762931a29c5eec8188e2aa25ed.zip | |
Add problem 20 .
Diffstat (limited to 'cpp/20.cpp')
| -rw-r--r-- | cpp/20.cpp | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/cpp/20.cpp b/cpp/20.cpp new file mode 100644 index 0000000..e994e96 --- /dev/null +++ b/cpp/20.cpp @@ -0,0 +1,55 @@ +#include <string>
+
+using std::string;
+
+#include <stack>
+
+class Solution
+{
+public:
+ inline static char get_companion(char c)
+ {
+ switch (c)
+ {
+ case ')':
+ return '(';
+ case ']':
+ return '[';
+ default:
+ return '{';
+ }
+ }
+
+ bool isValid(string s)
+ {
+ std::stack<char> stack;
+
+ for (const auto c : s)
+ {
+ switch (c)
+ {
+ case '(':
+ case '[':
+ case '{':
+ {
+ stack.push(c);
+ break;
+ }
+ case ')':
+ case ']':
+ default:
+ {
+ if (stack.empty())
+ return false;
+ const auto top = stack.top();
+ const char companion = get_companion(c);
+ if (top != companion)
+ return false;
+ stack.pop();
+ }
+ }
+ }
+
+ return stack.empty();
+ }
+};
|