/**

/**

bool equationsPossible(vector<string>& equations) {

// 并查集初始化

int set[30];

for (int i = 0; i < 30; ++i) set[i] = i;

for (const string &s : equations) {

if (s[1] == '=') {

join(set, s[0]-'a', s[3]-'a');

}

}

for (const string &s : equations) {

if (s[1] == '!') {

if (find(set, s[0]-'a') == find(set, s[3]-'a'))

return false;

}

}

return true;

}

char find(int *set, int x) {

if (set[x] == x) return x;

int res = find(set, set[x]); // 路径压缩算法

return res;

}

void join(int *set, int x, int y) {

int root_x = find(set, x);

int root_y = find(set, y);

set[root_y] = root_x;

}