algo1w4d2HEADmaster

1 files changed, 68 insertions, 0 deletions

diff --git a/algo1w4d2/BracketCheck.cpp b/algo1w4d2/BracketCheck.cpp
new file mode 100644
index 0000000..2584b75
--- /dev/null
+++ b/algo1w4d2/BracketCheck.cpp
@@ -0,0 +1,68 @@
+#include "BracketCheck.h"
+#include "Stack.h"
+
+BracketCheck::BracketCheck() { _stack = new Stack(); }
+BracketCheck::~BracketCheck() { delete _stack; }
+
+BracketCheck::BracketCheck(const std::string& s) : BracketCheck() {
+	for (char x : s) parse(std::string(1, x));
+}
+
+void BracketCheck::parse(const std::string& input) {
+	if (!_valid) return;
+	// match brackets
+	switch(input[0]) {
+		case '{': case '(': case '[': {
+			_stack->push(input);
+			break;
+		}
+		case '}': case ')': case ']': {
+			char open_bracket = _stack->pop()[0];
+			if (open_bracket == '{' && input[0] == '}') {
+				// _stack->pop(); // } is used to close blocks
+				break;
+			}
+			if (open_bracket == '(' && input[0] == ')') break;
+			if (open_bracket == '[' && input[0] == ']') break;
+			_valid = false;
+			break;
+		}
+	}
+
+	// check block ordering
+	switch(input[0]) {
+		case 'I': {
+			break;
+		}
+		case 'E': {
+			if (_stack->size() == 0) { _valid = false; break; }
+			if (_stack->peek()[0] != 'I') _valid = false;
+			break;
+		}
+		case 'D': {
+			break;
+		}
+		case 'W': {
+			if (_stack->size() > 0 && _stack->peek()[0] == 'D') { _stack->pop(); }
+			break;
+		}
+	}
+
+	// add blocks to stack
+	switch(input[0]) {
+		case 'I': case 'E': case 'D': case 'W': {
+			_stack->push(input);
+		}
+	}
+}
+
+bool BracketCheck::input_valid() {
+	while (_stack->size() > 0) {
+		char remainder = _stack->pop()[0];
+		switch(remainder) {
+			case '{': case '(': case '[': case 'D':
+				return false;
+		}
+	}
+	return _valid;
+}