20240617 lengli's submission for CF535D (Yawn-Sean#3700)

20240617 lengli's submission for CF535D

daily_problems/2024/06/0617/personal_submission/cf535d_lengli.cpp

@@ -0,0 +1,126 @@
+/*
+lengli_QAQ
+Hope there are no bugs!!!
+*/
+#include <bits/stdc++.h>
+#define fastio std::ios::sync_with_stdio(0); std::cin.tie(0); std::cout.tie(0)
+#define all(x) x.begin(),x.end()
+#define pb push_back
+
+template <unsigned M_> struct ModInt {
+  static constexpr unsigned M = M_;
+  unsigned x;
+  constexpr ModInt() : x(0U) {}
+  constexpr ModInt(unsigned x_) : x(x_ % M) {}
+  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
+  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
+  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
+  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
+  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
+  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
+  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
+  ModInt pow(long long e) const {
+    if (e < 0) return inv().pow(-e);
+    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
+  }
+  ModInt inv() const {
+    unsigned a = M, b = x; int y = 0, z = 1;
+    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
+    assert(a == 1U); return ModInt(y);
+  }
+  ModInt operator+() const { return *this; }
+  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
+  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
+  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
+  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
+  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
+  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
+  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
+  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
+  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
+  explicit operator bool() const { return x; }
+  bool operator==(const ModInt &a) const { return (x == a.x); }
+  bool operator!=(const ModInt &a) const { return (x != a.x); }
+  bool operator<(const ModInt &a) const { return (x < a.x); }
+  bool operator>(const ModInt &a) const { return (x > a.x); }
+  bool operator<=(const ModInt &a) const { return (x <= a.x); }
+  bool operator>=(const ModInt &a) const { return (x >= a.x); }
+  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
+  friend std::istream &operator>>(std::istream &is, ModInt &a) {int v;is >> v;a = ModInt(v);return is;}
+};
+constexpr unsigned MO = 1000000007;
+using Mint = ModInt<MO>;
+
+std::vector<int> z_function(std::string s){
+	int n = (int)s.size();
+	std::vector<int> z(n);
+	for (int i = 1, l = 0, r = 0; i < n; ++i) {
+        if (i <= r && z[i - l] < r - i + 1) {
+            z[i] = z[i - l];
+        } else {
+            z[i] = std::max(0, r - i + 1);
+            while (i + z[i] < n && s[z[i]] == s[i + z[i]]) ++z[i];
+        }
+	    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
+	}
+	return z;
+}
+
+void solve(){
+    int n,m;
+    std::cin>>n>>m;
+    std::string s;
+    std::cin>>s;
+    int len=s.size();
+    std::vector<int> idx(m);
+    for(auto &x:idx) std::cin>>x;
+    auto z=z_function(s);
+
+    sort(all(idx));
+
+    if(!m){
+        std::cout<<Mint(26).pow(n)<<"\n";
+        return;
+    }
+
+    if(idx[0]+len-1>n){
+        std::cout<<0<<"\n";
+        return;
+    }
+
+    int cnt=idx[0]-1;
+    int la=idx[0];
+    for(int i=1;i<m;i++){
+        int t=idx[i];
+        if(t-la>=len) {
+            cnt+=(t-(la+len));
+            if(t+len-1>n){
+                std::cout<<0<<"\n";
+                return;
+            }
+            la=t;
+        }else{
+            int k=z[t-la],nd=(len-(t-la));
+            if(k>=nd) {
+                la=t;
+                continue;
+            }else {
+                std::cout<<0<<"\n";
+                return;
+            }
+
+        }
+    }
+    cnt+=(n-(la+len-1));
+    std::cout<<Mint(26).pow(cnt)<<"\n";
+}
+
+signed main(){
+    fastio;
+
+    int T;
+    T=1;
+    while(T--) solve();
+
+    return 0;
+}