Submission #981346

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Source Code Expand

#pragma GCC optimize "-O3"
#include <iostream>
#include <fstream>
#include <set>
#include <map>
#include <string>
#include <vector>
#include <bitset>
#include <algorithm>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <cassert>
#include <queue>

#define mp make_pair
#define pb push_back


typedef long long ll;
typedef long double ld;

using namespace std;
const int MAXN = 1000100;

multiset<int> ss;
char s[MAXN];
char t[MAXN];
int lst[MAXN][26];
int n;
vector<pair<int, int> > vv;

int main() {
	scanf("%d", &n);
	scanf(" %s %s", s, t);
	if (strcmp(s, t) == 0) {
		cout << 0 << "\n";
		return 0;
	}
	for (int i = 0; i < 26; ++i)
		lst[0][i] = -1;
	lst[0][s[0] - 'a'] = 0;
	for (int i = 1; i < n; ++i) {
		for (int j = 0; j < 26; ++j)
			lst[i][j] = lst[i - 1][j];
		lst[i][s[i] - 'a'] = i;
	}
	int pr = n;
	for (int i = n - 1; i >= 0; --i) {
		pr = min(pr, i);
		if (pr < 0) {
			cout << -1 << "\n";
			return 0;
		}
		if (i != 0 && t[i] == t[i - 1])
			continue;
		if (lst[pr][t[i] - 'a'] == -1) {
			cout << -1 << "\n";
			return 0;
		}
		vv.push_back(make_pair(lst[pr][t[i] - 'a'], i));
		pr = min(pr, lst[pr][t[i] - 'a'] - 1);
	}
	int ans = 0;
	int dd = 0;
	for (int i = 0; i < (int)vv.size(); ++i) {
		dd -= 1;
		int x = vv[i].first;
		int y = vv[i].second;
		ss.insert(x - dd);
		while (!ss.empty() && *ss.rbegin() + dd >= y)
			ss.erase(prev(ss.end()));
		ss.insert(y - dd);
		ans = max(ans, (int)ss.size());
	}
	cout << ans << "\n";
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:34:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
./Main.cpp:35:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf(" %s %s", s, t);
                       ^

Judge Result