Submission #1798840

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Source Code Expand

#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <climits>
#include <iomanip>
#include <bitset>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <list>
#include <map>

using namespace std;

const int N = 100005;

string a;
string ans;
bool ok[3 * N];
int mid;

int main() {
  cin >> a;
  ans = string(N, 'x');
  ans += a[0];
  ok[ans.size() - 1] = 1;
  for (int i = 0; i < a.size() - 1; i++) {
    if (a[i] != 'x' && a[i + 1] != 'x') {
      ans += 'x';
    }
    ans += a[i + 1];
    ok[ans.size() - 1] = 1;
    if (i + 1 == a.size() / 2) {
      mid = ans.size() - 1;
    }
  }
  ans += string(N, 'x');
  int l, r;
  if (ans[mid - 1] == ans[mid]) {
    l = mid - 1;
    r = mid;
  } else if (ans[mid] == ans[mid + 1]) {
    l = mid;
    r = mid + 1;
  } else {
    l = r = mid;
  }
  int res = 0, lef, rig;
  while (l > 900) {
    if (ans[l] != ans[r]) {
      puts("-1");
      return 0;
    }
    if (ok[l] || ok[r]) {
      lef = l;
      rig = r;
    }
    l--;
    r++;
  }
  for (int i = lef; i <= rig; i++) {
    res += (!ok[i]);
  }
  printf("%d\n", res);
  return 0;
}

Submission Info

Judge Result