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import java.io.IOException;
public class BracketChecker {
private String input;
public BracketChecker(String in) {
input = in;
}
public void check() {
int stackSize = input.length();
Stack theStack = new Stack(stackSize);
for (int j = 0; j < input.length(); j++)
{
char ch = input.charAt(j);
switch (ch) {
case '{': // opening symbols
case '[':
case '(':
theStack.push(ch); // push them
break;
case '}': // closing symbols
case ']':
case ')':
if (!theStack.isEmpty()) // if stack not empty,
{
char chx = theStack.pop(); // pop and check
if ((ch == '}' && chx != '{') || (ch == ']' && chx != '[')
|| (ch == ')' && chx != '('))
System.out.println("Error: " + ch + " at " + j);
} else
// prematurely empty
System.out.println("Error: " + ch + " at " + j);
break;
default: // no action on other characters
break;
}
}
if (!theStack.isEmpty())
System.out.println("Error: missing right delimiter");
}
public static void main(String[] args) throws IOException {
String input = "{Java [Source] (and) {[(Support)]}}";
BracketChecker theChecker = new BracketChecker(input);
theChecker.check();
}
}
class Stack {
private int maxSize;
private char[] stackArray;
private int top;
public Stack(int max) {
maxSize = max;
stackArray = new char[maxSize];
top = -1;
}
public void push(char j) {
stackArray[++top] = j;
}
public char pop() {
return stackArray[top--];
}
public char peek() {
return stackArray[top];
}
public boolean isEmpty() {
return (top == -1);
}
}
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