#include <bits/stdc++.h>

using namespace std;

// Problem 7. Reverse Integer
// Medium

// Given a signed 32-bit integer x, return x with its digits
// reversed. If reversing x causes the value to go outside the signed
// 32-bit integer range [-2^31, 2^31 - 1], then return 0.

// Assume the environment does not allow you to store 64-bit integers
// (signed or unsigned).

class Solution {
public:        
    int reverse(int x) {
        deque<int> dq;

        if (x == 0) return 0;
        
        function<int(int)> getDigits = [&dq, &getDigits](int x) -> int
        {
            if ((x > 0 && x < 10) || (x < 0 && x > -10))
            {
                dq.push_back(x);
                return x;
            }
            
            int rem = x%10;
            dq.push_back(rem);
            x /= 10;
            
            return getDigits(x);
        };

        getDigits(x);

        cout << "deque: "; for (auto i: dq) {cout << i << " ";} cout << endl;
        
        int result = 0;
        for (size_t i = dq.size(); i > 0; i--)
        {
            cout << "pow: " << fixed<<  pow(10, i - 1) * dq.front() << endl;
            
            if (result + pow(10, i - 1) * dq.front() > INT_MAX ||
                result + pow(10, i - 1) * dq.front() < INT_MIN)
                return 0;
            
            result += pow(10, i - 1) * dq.front();
            dq.pop_front();
        }
        
        return result;
    }
};

int main()
{
    Solution s;
    vector<tuple<int,int>> testCases = {
        // {123,321},
        // {-123,-321},
        // {120,21},
        // {1534236469,0},
        //{-2147483648,0},
        {0,0},
        {1563847412,0},        
    };

    for (auto& test: testCases)
    {
        cout << setw(10) << "input: " << get<0>(test) << endl;
        int result = s.reverse(get<0>(test));
        cout << setw(10) << "result: " << result << endl;        
        cout << setw(10) << "expected: " << get<1>(test) << endl;        
        cout << "----------------" << endl;
    }


}