int maxIncreasingCells(vector<vector<int>>& mat) {
        int n = mat.size(), m = mat[0].size();
        unordered_map<int,vector<pair<int,int>>> mp;
        set<int> st;
        for(int i = 0; i < n; i++){
            for(int j = 0; j < m; j++){
                mp[mat[i][j]].push_back({i,j});
                st.insert(-mat[i][j]);
            }
        }
        vector<vector<int>> val(n, vector<int>(m));
        vector<int> rowPath(n), colPath(m);
        for(auto num : st){
            num = -num;
            for(auto pos : mp[num]){
                int r = pos.first;
                int c = pos.second;
                val[r][c] = max(rowPath[r], colPath[c]) + 1;
            }
            
            for(auto pos : mp[num]){
                int r = pos.first;
                int c = pos.second;
                rowPath[r] = max(rowPath[r], val[r][c]);
                colPath[c] = max(colPath[c], val[r][c]);
            }
        }
        int ans = 0;
        for(auto len : rowPath)
            ans = max(len ,ans);
        for(auto len : colPath)
            ans = max(len , ans);
        return ans;
    }