vector<int> diStringMatch(string S) {

int n = (int)S.length();

int low = 0, high = n;

vector<int> result;

for (int i = 0; i < n; i++) {

result.push_back(S[i] == 'D' ? high-- : low++);

}

assert(low == high);

result.push_back(high); // or low

return result;

}