Problem:
Score : 500 points

Problem Statement

Given are two strings s and t consisting of lowercase English letters. Determine if there exists an integer i satisfying the following condition, and find the minimum such i if it exists.

Let s' be the concatenation of 10^{100} copies of s. t is a subsequence of the string {s'}_1{s'}_2\ldots{s'}_i (the first i characters in s').

Notes

A subsequence of a string a is a string obtained by deleting zero or more characters from a and concatenating the remaining characters without changing the relative order. For example, the subsequences of contest include net, c, and contest.

Constraints

1 \leq |s| \leq 10^5

1 \leq |t| \leq 10^5

s and t consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

s
t

Output

If there exists an integer i satisfying the following condition, print the minimum such i; otherwise, print -1.

Sample Input 1

contest
son

Sample Output 1

10

t = son is a subsequence of the string contestcon (the first 10 characters in s' = contestcontestcontest...), so i = 10 satisfies the condition.

On the other hand, t is not a subsequence of the string contestco (the first 9 characters in s'), so i = 9 does not satisfy the condition.

Similarly, any integer less than 9 does not satisfy the condition, either. Thus, the minimum integer i satisfying the condition is 10.

Sample Input 2

contest
programming

Sample Output 2

-1

t = programming is not a substring of s' = contestcontestcontest.... Thus, there is no integer i satisfying the condition.

Sample Input 3

contest
sentence

Sample Output 3

33

Note that the answer may not fit into a 32-bit integer type, though we cannot put such a case here.

Solution in C++14 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <set>
#include <vector>
#include <map>

int main(int argc, char const *argv[])
{
  // std::string s;
  // std::cin >> s;
  char s[262144];
  scanf("%s", s);

  // std::string t;
  // std::cin >> t;
  char t[131072];
  scanf("%s", t);

  int sie = strlen(s);
  int tie = strlen(t);

  bool exist = true;

  std::set<char> sts;
  for (int i = 0; i < sie; i++)
  {
    sts.insert(s[i]);
  }


  std::set<char> stt;
  for (int i = 0; i < tie; i++)
  {
    stt.insert(t[i]);
  }

  for (auto &&c : stt)
  {
    if (sts.count(c) == 0)
    {
      exist = false;
      break;
    }
  }

  if (exist == false)
  {
    std::cout << -1 << std::endl;
    return 0;
  }

  // std::string ss = s + s;
  int *m[26];

  for (int i = 0; i < 26; i++)
  {
    m[i] = new int[sie];
  }

  for (int i = 0; i < sie; i++)
  {
    s[i + sie] = s[i];
  }

  int pos;
  for (int i = 0; i < sie; i++)
  {
    for (auto &&j : stt)
    {
      pos = 0;
      for (int k = i; k < sie * 2; k++)
      {
        if (j == s[k])
        {
          break;
        }
        pos++;
      }
      m[j - 97][i] = pos;
    }
  }

  long si = 0;
  int ti = 0;

  for (int i = 0; i < tie; i++)
  {
    int sip = si % sie;
    si += m[t[i] - 97][sip] + 1;
  }

  std::cout << si;

  return 0;
}