484. Find Permutation

class Solution {
public:
    vector<int> findPermutation(string s) {
        vector<int> res;
        for (int i = 0; i < s.size(); ) {
            while (i < s.size() && s[i] == 'I') {
                i++;
                res.push_back(res.size() + 1);
            }
            int j = i; 
            while (j < s.size() && s[j] != 'I') j++;
            int tmp = res.size() ;
            for (int k = j + 1; k > tmp; k--) res.push_back(k);
            i = j + 1;
        }
        if (res.size() == s.size()) res.push_back(s.size() + 1);
        return res;
    }
};