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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. using ll = long long int;
  4. #define inf 1000000000000000LL
  5. #define mod 1000000007LL
  6. #define FOR(i,a,b) for(int i = a; i < b; i++)
  7.  
  8. void solve() {
  9.     ll n,k;
  10.     cin >> n >> k;
  11.     vector <ll> l1(n);
  12.     ll cnt = 0;
  13.     FOR(i,0,n){
  14.         cin >> l1[i];
  15.         cnt += (i >= 1 ? l1[i] != l1[i-1] : 0);
  16.     }
  17.     deque <ll> spec;
  18.     vector <bool> good(n, false);
  19.     for (int i = 0; i < k; i++){
  20.         ll a;
  21.         cin >> a;
  22.         spec.push_back(a-1);
  23.         good[a-1] = true;
  24.     }
  25.     ll x = l1[spec[0]];
  26.     cnt += (l1[0] != x) + (l1[n-1] != x);
  27.  
  28.     ll v = (l1[0] != x);
  29.     ll max_val = v;
  30.     for (int i = 0; i < n; i++){
  31.         if (good[i]) v = 0;
  32.         if (i < n-1){
  33.             v += l1[i] != l1[i+1];
  34.             max_val = max(max_val, v);
  35.         }
  36.     }
  37.     v += l1[n-1] != x;
  38.     max_val = max(max_val, v);
  39.  
  40.     cout << max(cnt / 2, max_val) << "\n";
  41. }
  42.  
  43. int main() {
  44.     // ios::sync_with_stdio(false);
  45.     // cin.tie(nullptr);
  46.  
  47.     ll t = 1;
  48.     cin >> t;
  49.     while (t--) {
  50.         solve();
  51.     }
  52.  
  53.     return 0;
  54. }
Runtime error #stdin #stdout 0.04s 5292KB
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https://ideone.com/pOBXb0
language:
C++14 (clang 8.0)
created:
2 hours ago
visibility:
secret

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