class Solution {
        private int[] groups = new int[26];
        public boolean equationsPossible(String[] equations) {
            for(int i = 0; i < 26; i++) {
                groups[i] = i;
            }
            for(String s : equations) {
                if(s.charAt(1) == '=') {
                    union(s.charAt(0), s.charAt(3));
                }
            }
            
            for(String s : equations) {
                if(s.charAt(1) == '!') {
                    if(find(s.charAt(0) - 'a') == find(s.charAt(3) - 'a')) return false;
                }
            }
            return true;
        }
        
        private void union(Character a, Character b) {
            groups[find(a -'a')] = groups[find(b - 'a')];
        }
        
        private int find(int x) {
            if(x == groups[x]) return x;
            return groups[x] = find(groups[x]);
        }
    }