Educational Codeforces 71 C

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll inf = 1e17;
char s[200010];
ll ans[200010][2];
int main()
{
  int t;
  cin>>t;
  while(t--)
  {
      ll n,a,b;
      cin>>n>>a>>b;
      scanf("%s",s+1);
      ans[0][0] = b,ans[0][1] = inf;
      for(int i=1;i<=n;i++)
      {
          if(s[i] == '0'){
              ans[i][0] = min(ans[i-1][0],ans[i-1][1]+a)+a+b;
              ans[i][1] = min(ans[i-1][0]+a+b,ans[i-1][1])+a+2*b;
          }else{
              ans[i][0] = inf;
              ans[i][1] = min(ans[i-1][0]+a+b,ans[i-1][1])+a+2*b;
          }
      }
      cout<<ans[n][0]<<endl;
  }
  return 0;
}