#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, b) for(int i = 0; i < (int)b; i++)
#define FOR(i, a, b) for(int i = a; i < (int)b; i++)
#define dbg(v) cerr << "Line(" << __LINE__ << ") -> " << #v << " = " << (v) << endl;
#define debug(a, b) cerr << "[" << #a << ", " << #b << "] = [" << a << ", " << b << "]\n";
template<class T> inline void read(T& t){ cin >> t; }
template<class T, class... H> inline void read(T& t, H&... h){ cin >> t; read(h...); }
template<class T> inline void read(vector<T>& t){ for(auto&x : t) read(x); }
template<class T, class... H> inline void read(vector<T>& t, vector<H>&... h){ read(t); read(h...); }
template<class T> inline void wt(const T t) { cout << t; }
template<class T> inline void write(const T t) { cout << t << " "; }
template<class T> inline void print(const T t){ cout << t << "\n";}
template<class T, class... H> inline void wt(const T& t, const H&... h){ cout << t; wt(h...); }
template<class T, class... H> inline void print(const T& t, const H&... h){ cout << t; cout << " "; print(h...);}
#define all(x) x.begin(), x.end()
#define pb push_back
#define sz(a) (int)a.size()
bool bs(vector<int>&a, int x){
return binary_search(all(a), x);
}
int a, b, c;
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0);
int n, k; string s; read(n, k, s);
vector<int> pre_j(n + 1, 0), pre_o(n + 1, 0), pre_i(n + 1, 0);
// build prefix sum
rep(i, n){
pre_j[i + 1] = pre_j[i] + (s[i] == 'J');
pre_o[i + 1] = pre_o[i] + (s[i] == 'O');
pre_i[i + 1] = pre_i[i] + (s[i] == 'I');
}
int Min = 1e9, pos_j = 0, l = 0, cnt = 0, tmp = 0;
while(true){
if(bs(pre_j, pre_j[cnt] + k)){
pos_j = lower_bound(all(pre_j), pre_j[cnt] + 1) - pre_j.begin();
a = lower_bound(all(pre_j), pre_j[cnt++] + k) - pre_j.begin();
}else break;
if(bs(pre_o, pre_o[a] + k)){
b = lower_bound(all(pre_o), pre_o[a] + k) - pre_o.begin();
}else break;
if(bs(pre_i, pre_i[b] + k)){
c = lower_bound(all(pre_i), pre_i[b] + k) - pre_i.begin();
}else break;
// print(a, pos_j, b, c);
Min = min(Min, c - pos_j + 1 - 3 * k);
}
print(Min == (int)1e9 ? -1 : Min);
return 0;
}
/*
JOI 2020 JJOOII
- For each starting point...
- Find the next point such that the number of "J"s between it and the starting
point is equal to K
- Find the next point such that the number of "O"s between it and the previous
point is equal to K
- Find the next point such that the number of "I"s between it and the previous
point is equal to K
- Notice how this is always optimal because we want to minimize the distance
between the first and last points
- We can use 4 pointers and prefix sums to find the 4 points for each starting point
- Complexity: O(N)
*/
Compilation message
ho_t2.cpp: In function 'int main()':
ho_t2.cpp:39:31: warning: unused variable 'l' [-Wunused-variable]
39 | int Min = 1e9, pos_j = 0, l = 0, cnt = 0, tmp = 0;
| ^
ho_t2.cpp:39:47: warning: unused variable 'tmp' [-Wunused-variable]
39 | int Min = 1e9, pos_j = 0, l = 0, cnt = 0, tmp = 0;
| ^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
316 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
316 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
316 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
316 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
2 ms |
320 KB |
Output is correct |
17 |
Correct |
2 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
2 ms |
400 KB |
Output is correct |
21 |
Correct |
1 ms |
320 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
320 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
340 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
1 ms |
320 KB |
Output is correct |
29 |
Correct |
1 ms |
320 KB |
Output is correct |
30 |
Correct |
1 ms |
340 KB |
Output is correct |
31 |
Correct |
1 ms |
340 KB |
Output is correct |
32 |
Correct |
1 ms |
340 KB |
Output is correct |
33 |
Correct |
1 ms |
328 KB |
Output is correct |
34 |
Correct |
1 ms |
340 KB |
Output is correct |
35 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
316 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
316 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
2 ms |
320 KB |
Output is correct |
17 |
Correct |
2 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
2 ms |
400 KB |
Output is correct |
21 |
Correct |
1 ms |
320 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
320 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
340 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
1 ms |
320 KB |
Output is correct |
29 |
Correct |
1 ms |
320 KB |
Output is correct |
30 |
Correct |
1 ms |
340 KB |
Output is correct |
31 |
Correct |
1 ms |
340 KB |
Output is correct |
32 |
Correct |
1 ms |
340 KB |
Output is correct |
33 |
Correct |
1 ms |
328 KB |
Output is correct |
34 |
Correct |
1 ms |
340 KB |
Output is correct |
35 |
Correct |
1 ms |
340 KB |
Output is correct |
36 |
Correct |
52 ms |
5176 KB |
Output is correct |
37 |
Correct |
55 ms |
5524 KB |
Output is correct |
38 |
Correct |
51 ms |
5472 KB |
Output is correct |
39 |
Correct |
47 ms |
5472 KB |
Output is correct |
40 |
Correct |
14 ms |
5472 KB |
Output is correct |
41 |
Correct |
45 ms |
5440 KB |
Output is correct |
42 |
Correct |
53 ms |
5524 KB |
Output is correct |
43 |
Correct |
3 ms |
3540 KB |
Output is correct |
44 |
Correct |
4 ms |
4308 KB |
Output is correct |
45 |
Correct |
5 ms |
5444 KB |
Output is correct |
46 |
Correct |
7 ms |
5460 KB |
Output is correct |
47 |
Correct |
5 ms |
5444 KB |
Output is correct |
48 |
Correct |
5 ms |
5472 KB |
Output is correct |
49 |
Correct |
3 ms |
3808 KB |
Output is correct |
50 |
Correct |
5 ms |
5472 KB |
Output is correct |
51 |
Correct |
4 ms |
5472 KB |
Output is correct |
52 |
Correct |
4 ms |
5344 KB |
Output is correct |
53 |
Correct |
5 ms |
5472 KB |
Output is correct |
54 |
Correct |
20 ms |
5532 KB |
Output is correct |
55 |
Correct |
10 ms |
5472 KB |
Output is correct |
56 |
Correct |
5 ms |
5472 KB |
Output is correct |