class Solution

 {

 public:

     vector<int> shortestToChar(string S, char C)

     {

         int len=S.length();

         vector<int>res(len,-);                   //as the result vector

         vector<int> cindex;                       //save the index of C

         for(int i=;i<len;i++)                    //write the distance of C and build the cindex

             if(S[i]==C)

             {

                 cindex.push_back(i);

                 res[i]=;

             }

         int szindex=cindex.size();

         int count=;

         for(int j=cindex[]-;j>=;j--)           //write the distance before the first C

             res[j]=count++;

         count=;

         for(int k=cindex[szindex-]+;k<len;k++)  //write the distance after the last C

             res[k]=count++;

         for(int x=;x<szindex;x++)                //write the distance between two C

         {

             count=;

             int left=cindex[x-]+,right=cindex[x]-;

             while(left<=right)

             {

                 res[left++]=count;

                 res[right--]=count++;

             }

         }

         return res;

     }

 };