Algorithm-Collection/Data Structures/Stack/Stack.java at master · bringani/Algorithm-Collection · GitHub

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classStack {
staticfinalintMAX = 100; // Maximum size of Stack
inttop;
inta[] = newint[MAX];
Stack() { top = -1; }

booleanpush(intx) {
if (top >= (MAX - 1)) {
System.out.println("Stack Overflow");
returnfalse;
 }
else {
a[++top] = x;
returntrue;
 }
 }

intpop() {
if (top < 0) {
System.out.println("Stack Underflow");
return0;
 }
else {
intx = a[top--];
returnx;
 }
 }

intpeek() {
if (top < 0) {
System.out.println("Stack Underflow");
return0;
 }
else {
intx = a[top];
returnx;
 }
 }

booleanisEmpty() {
return (top < 0);
 }
}

// Driver code
classMain {
publicstaticvoidmain(Stringargs[])
 {
Stackstk = newStack();
stk.push(1);
stk.push(2);
stk.push(3);
System.out.println("1, 2, 3 added to stack");

// Pop up Stack
System.out.println(stk.pop() + " Popped from stack");

// Get the top values
System.out.println(stk.peek() + " is the peek value");

// isEmpty
if (stk.isEmpty()){
System.out.println("Empty");
 }
else {
System.out.println("Not empty");
 }
 }
}