Make Two Arrays Equal by Reversing Sub-arrays Solutions in C++

// Source : https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays/
// Author : Hao Chen
// Date   : 2020-10-02


class Solution {
public:
    // This problem could transfer to check two array has exactly same numbers
    bool canBeEqual(vector<int>& target, vector<int>& arr) {
       
       
        int len1 = target.size();
        int len2 = arr.size();
        if (len1 != len2) return false;
        if (len1 == 0) return true;
        
        unordered_map<int, int> stat;
        for (int i=0; i<len1; i++) {
            stat[target[i]]++;
            stat[arr[i]]--;
        }
        
        for (auto& s:stat) {
            if (s.second !=0 ) return false;
        }
        return true;
    }
    
};

/// Source : https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays/
/// Author : liuyubobobo
/// Time   : 2020-05-30

#include <iostream>
#include <vector>

using namespace std;


/// Sorting
/// Time Complexity: O(nlogn)
/// Space Complexity: O(1)
class Solution {
public:
    bool canBeEqual(vector<int>& target, vector<int>& arr) {

        sort(target.begin(), target.end());
        sort(arr.begin(), arr.end());
        return target == arr;
    }
};


int main() {

    return 0;
}

/// Source : https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays/
/// Author : liuyubobobo
/// Time   : 2020-05-30

#include <iostream>
#include <vector>
#include <unordered_map>

using namespace std;


/// Using Hash Map
/// Time Complexity: O(n)
/// Space Complexity: O(n)
class Solution {
public:
    bool canBeEqual(vector<int>& target, vector<int>& arr) {

        unordered_map<int, int> f1, f2;
        for(int i = 0; i < target.size(); i ++)
            f1[target[i]] ++, f2[arr[i]] ++;
        return f1 == f2;
    }
};


int main() {

    return 0;
}