di-string-match.cpp

//question//


A permutation perm of n + 1 integers of all the integers in the range [0, n] can be represented as a string s of length n where:

s[i] == 'I' if perm[i] < perm[i + 1], and
s[i] == 'D' if perm[i] > perm[i + 1].
Given a string s, reconstruct the permutation perm and return it. If there are multiple valid permutations perm, return any of them.

 

Example 1:

Input: s = "IDID"
Output: [0,4,1,3,2]
Example 2:

Input: s = "III"
Output: [0,1,2,3]
Example 3:

Input: s = "DDI"
Output: [3,2,0,1]
 

Constraints:

1 <= s.length <= 105
s[i] is either 'I' or 'D'.



//solution//


class Solution {
public:
    vector<int> diStringMatch(string s) {
        vector<int> v;
        int n = s.size();
        int start = 0;
        for(int i=0;s[i]!='\0';i++)
        {
            if(s[i]=='I')
            {
                v.push_back(start);
                start++;
            }
            else
            {
                v.push_back(n);
                n--;
            }
        }
        v.push_back(start);
        return v;
    }
};