Submission #400045

#	Time	Username	Problem	Language	Result	Execution time	Memory
400045		SavicS	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	11 ms	3192 KiB

ho_t2

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>

#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ff(i,a,b) for(int i=a;i<=b;i++)
#define fb(i,b,a) for(int i=b;i>=a;i--)

using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
const int maxn = 200005;
const int inf = 1e9 + 5;

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

int n, K;
string s;

int ptr[4];
int pref[maxn][3];

int f(char C){
   if(C == 'J')return 1;
   if(C == 'O')return 2;
   if(C == 'I')return 3;
   assert(false);
}

int main()
{
   ios::sync_with_stdio(false);
   cout.tie(nullptr);
   cin.tie(nullptr);
   cin >> n >> K >> s;
   s = ' ' + s;

   ff(i,1,n){
      ff(j,1,3)pref[i][j] = pref[i - 1][j];
      pref[i][f(s[i])] += 1;
   }

   int rez = inf;
   for(ptr[0] = 0; ptr[0] <= n; ptr[0] += 1){
      ff(i,1,3){
         while (ptr[i] < ptr[i - 1] || (ptr[i] <= n && pref[ptr[i]][i] - pref[ptr[i - 1]][i] < K)){
                ptr[i]++;
         }
      }

      bool ok = 1;
      ff(i,1,3)ok &= (ptr[i] <= n && pref[ptr[i]][i] - pref[ptr[i - 1]][i] >= K);

      if(ok)rez = min(rez, ptr[3] - ptr[0] - 3 * K);

   }

   cout << (rez == inf ? -1 : rez) << endl;

   return 0;
}
/**

9 3
JJJOOOIII

// probati bojenje sahovski ili slicno

**/

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:49:42: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
   49 |       ff(j,1,3)pref[i][j] = pref[i - 1][j];
      |                             ~~~~~~~~~~~~~^
ho_t2.cpp:11:32: note: within this loop
   11 | #define ff(i,a,b) for(int i=a;i<=b;i++)
......
   49 |       ff(j,1,3)pref[i][j] = pref[i - 1][j];
      |          ~~~~~                  
ho_t2.cpp:49:7: note: in expansion of macro 'ff'
   49 |       ff(j,1,3)pref[i][j] = pref[i - 1][j];
      |       ^~
ho_t2.cpp:49:42: warning: array subscript 3 is above array bounds of 'int [3]' [-Warray-bounds]
   49 |       ff(j,1,3)pref[i][j] = pref[i - 1][j];
      |                             ~~~~~~~~~~~~~^
ho_t2.cpp:49:25: warning: array subscript 3 is above array bounds of 'int [3]' [-Warray-bounds]
   49 |       ff(j,1,3)pref[i][j] = pref[i - 1][j];
      |                ~~~~~~~~~^

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87