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Submission #167935

# Submission time Handle Problem Language Result Execution time Memory
167935 2019-12-10T21:43:14 Z Thuleanx Difference (POI11_roz) C++14
100 / 100
 747 ms 2580 KB 
#include <bits/stdc++.h>
using namespace std;

const int M = 26;
int n;
string s;

int best[M][M];
int invalid[M][M];
int update_local[M];
int update_global[M];

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	cin>>n>>s;
	int ans = 0;

	for (int _ = 0; _ < 2; _++) {
		for (int i = 0; i < M; i++) {
			for (int j = 0; j < M; j++)
				best[i][j] = invalid[i][j] = -1e9;
			update_local[i] = update_global[i] = 0;
		}
		for (int i = 0; i < n; i++) {
			// [i][s[i]-'a']--
			update_global[s[i]-'a']--;
			// [s[i]-'a'][i]++
			update_local[s[i]-'a']++;

			for (int c = 0; c < M; c++) if (c != s[i]-'a') {
				// make things valid
				best[c][s[i]-'a'] = max(best[c][s[i]-'a'], invalid[c][s[i]-'a']);
				best[c][s[i]-'a'] = max(best[c][s[i]-'a'], -1-update_local[c]-update_global[s[i]-'a']);
				ans = max(ans, best[s[i]-'a'][c] + update_local[s[i]-'a'] + update_global[c]);

				// now new updates are invalid until activated
				invalid[s[i]-'a'][c] = max(invalid[s[i]-'a'][c], 1 - update_local[s[i]-'a'] - update_global[c]);
			}
		}
		cout << endl;
		reverse(begin(s), end(s));
	}


	cout << ans << endl;

	return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 380 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 504 KB Output is correct
2 Correct 2 ms 376 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 376 KB Output is correct
2 Correct 2 ms 348 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 700 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 17 ms 376 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 746 ms 2448 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 609 ms 2316 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 746 ms 2476 KB Output is correct
2 Correct 599 ms 2188 KB Output is correct
3 Correct 634 ms 2196 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 747 ms 2548 KB Output is correct
2 Correct 746 ms 2580 KB Output is correct
3 Correct 731 ms 2448 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 745 ms 2472 KB Output is correct
2 Correct 739 ms 2520 KB Output is correct
3 Correct 733 ms 2476 KB Output is correct