Submission #203552

#	Time	Username	Problem	Language	Result	Execution time	Memory
203552		arman_ferdous	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	13 ms	2936 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;

const int N = 2e5+100;
int n, k;
char s[N];

int J[N], O[N], I[N];

int main() {
	scanf("%d %d %s", &n, &k, s + 1);

	int ptr = -1, cnt = 0;
	for(int i = 1; i <= n; i++) {
		while(ptr + 1 <= n && cnt < k) {
			ptr++;
			if(s[ptr] == 'J') cnt++;
		}
		if(cnt == k) J[i] = ptr;
		if(s[i] == 'J') cnt--;
	} ptr = -1, cnt = 0;
	for(int i = 1; i <= n; i++) {
		while(ptr + 1 <= n && cnt < k) {
			ptr++;
			if(s[ptr] == 'O') cnt++;
		}
		if(cnt == k) O[i] = ptr;
		if(s[i] == 'O') cnt--;
	} ptr = -1, cnt = 0;
	for(int i = 1; i <= n; i++) {
		while(ptr + 1 <= n && cnt < k) {
			ptr++;
			if(s[ptr] == 'I') cnt++;
		}
		if(cnt == k) I[i] = ptr;
		if(s[i] == 'I') cnt--;
	}

	int ans = n * 3;
	for(int i = 1; i <= n; i++) {
		int to = I[O[J[i]]];
		if(to >= i) ans = min(ans, to - i + 1 - 3 * k);
	}
	if(ans == n * 3) ans = -1;
	printf("%d\n", ans);
	return 0;
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:11:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %s", &n, &k, s + 1);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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