Spiral Matrix

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
        vector<int> ans;
        int n = matrix.size(),m = matrix[0].size();
        int num = min(n,m);
        if(m == 1 || n == 1){
            for(int i = 0;i < matrix.size();i++){
            for(int j = 0;j < matrix[0].size();j++){
                ans.push_back(matrix[i][j]);
            }
        }
            return ans;
        }
        unordered_map<int,int> mp;
        int low = 0,high = m-1,count = 0;
        int low2 = 1,high2 = n-1,count2 = m-1;
        int low3 = m-1,high3 = 0,count3 = n-1;
        int low4 = n-1,high4 = 1,count4 = 0;
        for(int i = 0;i < matrix.size();i++){
            for(int j = 0;j < matrix[0].size();j++){
                mp[matrix[i][j]]++;
            }
        }
        while(num--){
            for(int i = low;i <= high;i++){
                if(mp[matrix[count][i]]){
                ans.push_back(matrix[count][i]);
                mp[matrix[count][i]]--;
                }
            }
            for(int i = low2;i <= high2;i++){
                if(mp[matrix[i][count2]])
                {
                ans.push_back(matrix[i][count2]);
                mp[matrix[i][count2]]--;
                }
            }
            for(int i = low3-1;i >= high3;i--){
                if(mp[matrix[count3][i]]){
                ans.push_back(matrix[count3][i]);
                mp[matrix[count3][i]]--;
                }
            }
            for(int i = low4-1;i >= high4;i--){
                if(mp[matrix[i][count4]]){
                ans.push_back(matrix[i][count4]);
                mp[matrix[i][count4]]--;
                }
            }
            low++,high--,low2++,high2--,low3--,high3++,low4--,high4++;
            count++,count2--,count3--,count4++;
        }
        return ans;
    }
};