Min Stack

class MinStack {
    vector<int> inputNum;
    vector<int> minNum;
    
public:
    void push(int x) {
        inputNum.push_back(x);
        int n = minNum.size();
        if ((!n) || (n && x <= minNum[n - 1])) {
            minNum.push_back(x);
        }
    }

    void pop() {
        int inputSize = inputNum.size();
        if (!inputSize) return;
        int minSize = minNum.size();
        if (inputNum[inputSize - 1] == minNum[minSize - 1]) {
            minNum.pop_back();
        }
        inputNum.pop_back();
    }

    int top() {
        int n = inputNum.size();
        if (!n) return 0;
        return inputNum[n - 1];
    }

    int getMin() {
        int n = minNum.size();
        if (!n) return 0;
        return minNum[n - 1];
    }
};