数据结构——括号的匹配

1.    代码实现

#include <stdbool.h>
#include <stdio.h>
#include <malloc.h>

#define STACK_MAX_SIZE 10

typedef struct CharStack {
	int top;

	char data[STACK_MAX_SIZE];
} *CharStackPtr;

void outputStack(CharStackPtr paraStack) {
	for (int i = 0; i <= paraStack->top; i++) {
		printf("%c ", paraStack->data[i]);
	}
	printf("\n");
}
CharStackPtr charStackInit() {
	CharStackPtr resultPtr = (CharStackPtr)malloc(sizeof(struct CharStack));
	resultPtr->top = -1;

	return resultPtr;
}
void push(CharStackPtr paraStackPtr, int paraValue) {

	if (paraStackPtr->top >= STACK_MAX_SIZE - 1) {
		printf("Cannot push element: stack full.\r\n");
		return;
	}
	paraStackPtr->top++;
	paraStackPtr->data[paraStackPtr->top] = paraValue;
}


char pop(CharStackPtr paraStackPtr) {

	if (paraStackPtr->top < 0) {
		printf("Cannot pop element: stack empty.\r\n");
		return '\0';
	}
	paraStackPtr->top--;

	return paraStackPtr->data[paraStackPtr->top + 1];
}
void pushPopTest() {
	printf("---- pushPopTest begins. ----\r\n");
	char ch;

	CharStackPtr tempStack = charStackInit();
	printf("After initialization, the stack is: ");
	outputStack(tempStack);

	for (ch = 'a'; ch < 'm'; ch++) {
		printf("Pushing %c.\r\n", ch);
		push(tempStack, ch);
		outputStack(tempStack);
	}
	for (int i = 0; i < 3; i++) {
		ch = pop(tempStack);
		printf("Pop %c.\r\n", ch);
		outputStack(tempStack);
	}

	printf("---- pushPopTest ends. ----\r\n");
}

bool bracketMatching(char* paraString, int paraLength) {
	CharStackPtr tempStack = charStackInit();
	push(tempStack, '#');
	char tempChar, tempPopedChar;

	for (int i = 0; i < paraLength; i++) {
		tempChar = paraString[i];

		switch (tempChar) {
		case '(':
		case '[':
		case '{':
			push(tempStack, tempChar);
			break;
		case ')':
			tempPopedChar = pop(tempStack);
			if (tempPopedChar != '(') {
				return false;
			}
			break;
		case ']':
			tempPopedChar = pop(tempStack);
			if (tempPopedChar != '[') {
				return false;
			}
			break;
		case '}':
			tempPopedChar = pop(tempStack);
			if (tempPopedChar != '{') {
				return false;
			} 
			break;
		default:
			break;
		}
	}

	tempPopedChar = pop(tempStack);
	if (tempPopedChar != '#') {
		return false;
	} 
	return true;
}


void bracketMatchingTest() {
	char* tempExpression = (char*)"[2 + (1 - 3)] * 4";
	bool tempMatch = bracketMatching(tempExpression, 17);
	printf("Is the expression '%s' bracket matching? %d \r\n", tempExpression, tempMatch);


	tempExpression = (char*)"( )  )";
	tempMatch = bracketMatching(tempExpression, 6);
	printf("Is the expression '%s' bracket matching? %d \r\n", tempExpression, tempMatch);

	tempExpression = (char*)"()()(())";
	tempMatch = bracketMatching(tempExpression, 8);
	printf("Is the expression '%s' bracket matching? %d \r\n", tempExpression, tempMatch);

	tempExpression = (char*)"({}[])";
	tempMatch = bracketMatching(tempExpression, 6);
	printf("Is the expression '%s' bracket matching? %d \r\n", tempExpression, tempMatch);


	tempExpression = (char*)")(";
	tempMatch = bracketMatching(tempExpression, 2);
	printf("Is the expression '%s' bracket matching? %d \r\n", tempExpression, tempMatch);
}

int main() {
	bracketMatchingTest();
	return 0;
}

2.    运行结果

3.    总结

括号匹配是一种对栈的应用方法，栈的运用很广泛，学会栈有很大的帮助。