Submission #64086279

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Source Code Expand

#include <bits/stdc++.h>
#define int long long

using namespace std;

const int N = 1e6 + 5, Mod = 998244353;

char s[N];
int n, a[N], cnt, h1[N], h2[N], p[N];

int Hash1(int l, int r) {
  return (h1[r] + Mod - h1[l - 1] * p[r - l + 1] % Mod) % Mod;
}

int Hash2(int l, int r) {
  return (h2[l] + Mod - h2[r + 1] * p[r - l + 1] % Mod) % Mod;
}

signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
  cin >> s + 1, n = strlen(s + 1), p[0] = 1;
  for (int i = 1; i <= n; ++i) {
    p[i] = p[i - 1] * 26 % Mod;
  }
  for (int i = 1; i <= n; ++i) {
    h1[i] = (h1[i - 1] * 26 + s[i]) % Mod;
  }
  for (int i = n; i; --i) {
    h2[i] = (h2[i + 1] * 26 + s[i]) % Mod;
  }
  for (int i = n >> 1, pos; ~i; --i) {
    if ((i << 1 | 1) <= n && Hash1(n - i + 1, n) == Hash2(n - i * 2, n - i - 1)) {
      pos = n - i * 2 - 1;
      while (pos >= 1) {
        s[++n] = s[pos--];
      }
      break;
    } else if (Hash1(n - i + 1, n) == Hash2(n - i * 2 + 1, n - i)) {
      pos = n - i * 2;
      while (pos >= 1) {
        s[++n] = s[pos--];
      }
      break;
    }
  }
  cout << s + 1;
  return 0;
}

Submission Info

Compile Error

Main.cpp: In function ‘int main()’:
Main.cpp:22:12: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses]
   22 |   cin >> s + 1, n = strlen(s + 1), p[0] = 1;
      |          ~~^~~

Judge Result