leetcode 155. Min Stack
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.
pop() -- Removes the element on top of the stack.
top() -- Get the top element.
getMin() -- Retrieve the minimum element in the stack.
Example:
MinStack minStack = new MinStack();
minStack.push(-2);
minStack.push(0);
minStack.push(-3);
minStack.getMin(); --> Returns -3.
minStack.pop();
minStack.top(); --> Returns 0.
minStack.getMin(); --> Returns -2.
class MinStack {
static int min = 2147483647;
static int top = 0;
static int[] array;
public MinStack() {
min = 2147483647;
top =0;
array = new int;
}
public void push(int x) {
if(x < min) min = x;
array = x;
}
public void pop() {
if(top() == min) getNewMin();
top--;
}
public int top() {
return array;
}
public int getMin() {
return min;
}
public void getNewMin(){
min = 2147483647;
for(int i = 0; i< top-1; i++){
if(array < min) min = array;
}
}
}
/**
* Your MinStack object will be instantiated and called as such:
* MinStack obj = new MinStack();
* obj.push(x);
* obj.pop();
* int param_3 = obj.top();
* int param_4 = obj.getMin();
*/
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