Submission #931794

#	Time	Username	Problem	Language	Result	Execution time	Memory
931794		Baizho	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	6 ms	4900 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
  
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
 
// #pragma GCC optimize("Ofast,unroll-loops,fast-math")
// #pragma GCC target("popcnt")
 
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll,ll> pll;
 
#define sz size()
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define pb push_back
 
const int mod = ll(1e9)+7; //(b + (a%b)) % b (to mod -1%(10^9+7) correctly in c++ its -1 but its suppose to be 10^9+6
const ll MOD = 998244353;  // (a%mod)*(binpow(b,mod-2,mod) = (a/b)%mod
const int N = ll(2e3)+100;
const int M = ll(2e5) + 100;
const long long inf = 5e18;
const long double eps = 1e-15L;
 
ll lcm(ll a, ll b) { return (a / __gcd(a,b))*b; }
 
ll binpow(ll a, ll b, ll m) { ll res=1; a %= m; while(b>0){ if(b&1)res=(res * a) % m; a=(a * a) % m; b/=2; } return res%m;}
 
void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
 

void Baizho() {
	int n, k; cin>>n>>k;
	string s; cin>>s;
	s = '$' + s;
	vector<int> dp1(n + 2), dp2(n + 2), pref(n + 2), suf(n + 2);
	vector<int> poso;
	queue<int> pos;
	for(int i = 1; i <= n; i ++) {
		pref[i] = pref[i - 1];
		if(s[i] == 'J') {
			pref[i] ++;
			pos.push(i);
			if(pos.size() > k) {
				int p = pos.front();
				pos.pop();
				dp1[i] = dp1[i - 1] - pos.front() + p + 1;
			} else dp1[i] = dp1[i - 1];
		} else {
			if(s[i] == 'O') poso.pb(i);
			if(!pos.empty()) dp1[i] = dp1[i - 1] + 1;
		}
//		cout<<dp1[i]<<" ";
	}
	while(!pos.empty()) pos.pop();
	for(int i = n; i >= 1; i --) {
		suf[i] = suf[i + 1];
		if(s[i] == 'I') {
			suf[i] ++;
			pos.push(i);
			if(pos.size() > k) {
				int p = pos.front();
				pos.pop();
				dp2[i] = dp2[i + 1] - p + pos.front() + 1;
			} else dp2[i] = dp2[i + 1];
		} else {
			if(!pos.empty()) dp2[i] = dp2[i + 1] + 1;
		}
	}
	int ans = 1e9;
	for(int i = 0; i + k - 1 < poso.size(); i ++) {
		int j = i + k - 1, l = poso[i], r = poso[j];
		if(pref[l - 1] < k || suf[r + 1] < k) continue;
		ans = min(ans, dp1[l - 1] + dp2[r + 1] + (r - l + 1) - k);
	}
	if(ans == 1e9) ans = -1;
	cout<<ans<<"\n";
	
}
 
signed main() {		
// 	Freopen("nondec");
    ios_base::sync_with_stdio(false);   
    cin.tie(0);cout.tie(0); 
//   	precalc();
   	
    int ttt = 1;
//    cin>>ttt;
 
    for(int i=1; i<=ttt; i++) {Baizho(); }
}

Compilation message (stderr)

ho_t2.cpp: In function 'void Baizho()':
ho_t2.cpp:50:18: warning: comparison of integer expressions of different signedness: 'std::queue<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   50 |    if(pos.size() > k) {
      |       ~~~~~~~~~~~^~~
ho_t2.cpp:67:18: warning: comparison of integer expressions of different signedness: 'std::queue<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   67 |    if(pos.size() > k) {
      |       ~~~~~~~~~~~^~~
ho_t2.cpp:77:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |  for(int i = 0; i + k - 1 < poso.size(); i ++) {
      |                 ~~~~~~~~~~^~~~~~~~~~~~~
ho_t2.cpp: In function 'void Freopen(std::string)':
ho_t2.cpp:35:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t2.cpp:35:76: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                                                                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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