Submission #364835

#	Time	Username	Problem	Language	Result	Execution time	Memory
364835		cpp219	JJOOII 2 (JOI20_ho_t2)	C++14	13 / 100	2072 ms	2100 KiB

ho_t2

#include <bits/stdc++.h>
#define ll int
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 2e5 + 3;
const ll inf = 1e9 + 7;
typedef pair<int,int> LL;
string s;
ll n,k;
vector<ll> J,O,I;

ll Forwardk(ll pos,vector<ll> v){
    ll now = lower_bound(v.begin(),v.end(),pos) - v.begin();
    now += k - 1;
    if (now < v.size()) return v[now];
    return -1;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    #define task "tst"
    if (fopen(task".INP","r")){
        freopen(task".INP","r",stdin);
        //freopen(task".OUT","w",stdout);
    }
    cin>>n>>k>>s; s = " " + s;
    for (ll i = 1;i <= n;i++){
        if (s[i] == 'J') J.push_back(i);
        if (s[i] == 'O') O.push_back(i);
        if (s[i] == 'I') I.push_back(i);
    }
    ll ans = inf;
    for (ll i = 1;i <= n;i++){
        if (s[i] != 'J') continue;
        ll p = Forwardk(i,J); if (p == -1) break;
        p = Forwardk(p,O); if (p == -1) break;
        p = Forwardk(p,I); if (p == -1) break;
        ans = min(ans,p - i + 1 - 3*k);
    }
    cout<<(ans == inf ? -1 : ans);
}

Compilation message (stderr)

ho_t2.cpp: In function 'int Forwardk(int, std::vector<int>)':
ho_t2.cpp:17:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     if (now < v.size()) return v[now];
      |         ~~~~^~~~~~~~~~
ho_t2.cpp: In function 'int main()':
ho_t2.cpp:26:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   26 |         freopen(task".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 0 / 87