class Solution {
public:
    int minCost(string s, vector<int>& cost) {
        int ans = 0;
        char pre = s[0];
        int pre_id = 0;
        for(int i=1; i<s.size(); ++i)
        {
            if(s[i]==pre)
            {
                if(cost[i]<cost[pre_id])
                {
                    ans += cost[i];
                }
                else
                {
                    ans += cost[pre_id];
                    pre = s[i];
                    pre_id = i;
                }
            }
            else
            {
                pre = s[i];
                pre_id = i;
            }
        }

        return ans;
    }
};