Min Stack

class MinStack:

    def __init__(self):
        self.stack = []
        self.min_stack = []

    def push(self, val: int) -> None:
        self.stack.append(val)
        if not self.min_stack or val <= self.min_stack[-1]:
            self.min_stack.append(val)

    def pop(self) -> None:
        val = self.stack.pop()
        if val == self.min_stack[-1]:
            self.min_stack.pop()

    def top(self) -> int:
        return self.stack[-1]

    def getMin(self) -> int:
        return self.min_stack[-1]

# Your MinStack object will be instantiated and called as such:
# obj = MinStack()
# obj.push(val)
# obj.pop()
# param_3 = obj.top()
# param_4 = obj.getMin()

class MinStack {
private:
    stack<int> st;
    stack<int> min_st;
public:
    MinStack() {

    }

    void push(int val) {
        st.push(val);
        if (min_st.empty() || val <= min_st.top()) {
            min_st.push(val);
        }
    }

    void pop() {
        int val = st.top();
        st.pop();
        if (val == min_st.top()) {
            min_st.pop();
        }
    }

    int top() {
        return st.top();
    }

    int getMin() {
        return min_st.top();
    }
};

/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack* obj = new MinStack();
 * obj->push(val);
 * obj->pop();
 * int param_3 = obj->top();
 * int param_4 = obj->getMin();
 */

class MinStack {
    private stack: number[] = [];
    private minStack: number[] = [];

    push(val: number): void {
        this.stack.push(val);
        if (this.minStack.length === 0 || val <= this.minStack[this.minStack.length - 1]) {
            this.minStack.push(val);
        }
    }

    pop(): void {
        const val = this.stack.pop();
        if (val === this.minStack[this.minStack.length - 1]) {
            this.minStack.pop();
        }
    }

    top(): number {
        return this.stack[this.stack.length - 1];
    }

    getMin(): number {
        return this.minStack[this.minStack.length - 1];
    }
}