func_code_string: #include <bits/stdc++.h>   using namespace std;   long long pow(long long b, long long e, long long m) {     long long t = 1;     for (; e; e >>= 1, b = b * b % m) e & 1 ? t = t * b % m : 0;     return t;   }   template <class T>   inline bool chkmin(T &a, T b) {     return a > b ? a = b, true : false;   }   template <class T>   inline bool chkmax(T &a, T b) {     return a < b ? a = b, true : false;   }   template <class T>   inline T sqr(T x) {     return x * x;   }   template <typename T>   T gcd(T x, T y) {     for (T t; x; t = x, x = y % x, y = t)       ;     return y;   }   template <class edge>   struct Graph {     vector<vector<edge> > adj;     Graph(int n) {       adj.clear();       adj.resize(n + 5);     }     Graph() { adj.clear(); }     void resize(int n) { adj.resize(n + 5); }     void add(int s, edge e) { adj[s].push_back(e); }     void del(int s, edge e) { adj[s].erase(find(iter(adj[s]), e)); }     vector<edge> &operator[](int t) { return adj[t]; }   };   string S, T;   map<pair<char, char>, int> f;   int main() {     ios_base::sync_with_stdio(false);     cin >> S >> T;     int n = (int)((S).size()), m = (int)((T).size()), L = 0, R = 0;     long long ans = 0;     for (int i = 0; i < n; ++i) {       for (; R < m - 1 && T[R] != S[i]; ++R) ++f[make_pair(T[R], T[R + 1])];       ans += R - L + 1;       if (i < n - 1 && S[i] != S[i + 1]) ans -= f[make_pair(S[i + 1], S[i])];       if (T[L] == S[i]) --f[make_pair(T[L], T[L + 1])], ++L;       if (R < m - 1) ++f[make_pair(T[R], T[R + 1])], ++R;       if (L == m) break;     }     cout << ans << endl;     return 0;   }   