提出 #60107109

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ソースコード 拡げる

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define edl cout << '\n';
#define vct vector
#define pb push_back
#define pii pair<int, int> 
#define pll pair<ll, ll>
#define fi first
#define se second
#define que queue
#define stk stack
#define sct struct
#define str string
#define rep(i, l, r) for (int i = l; i <= r; i ++)
const int N = 2e5 + 10;
//const int mod 
int a[N];
int cnt[N];
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
//	freopen(".in", "r", stdin);
//	freopen(".out", "w", stdout);
	int n;
	cin >> n;
	rep(i, 1, n) cin >> a[i];
	int maxx = 0;
	int l = 1, r = 0;
	while (l < n && r <= n) {
//		cout << l << ' ' << r << '\n';
//		cout << cnt[1] << ' ' << cnt[2] << ' ' << cnt[3] << '\n';
//		if (l == 5 && r == 4) rep(i, 1, n) cout << cnt[a[]] 
		if (r + 2 <= n && a[r+1]==a[r+2] && !cnt[a[r+1]]) {
			cnt[a[r+1]] += 2;
			r += 2;
		} else {
//			cout << "*";
			maxx = max(maxx, r - l + 1);
			if (a[r+1]!=a[r+2] && r + 2 <= n) {//防止数组越界 
//			cout << '&';
				while (l <= r) {
					cnt[l++]--;
				}
				l += 2;
				r = l - 1;
			} else if (cnt[a[r+1]]){
				do {
					cnt[a[l]] -= 2;
					l += 2;
				}while (a[l-1] != a[r+1]) ;
			} else {
//				cout << '(';
				break;
			}
			
		}
	} 
	memset(cnt, 0, sizeof cnt);
	l = 2, r = 1;
	while (l < n && r <= n) {
//		cout << l << ' ' << r << '\n';
//		cout << cnt[1] << ' ' << cnt[2] << ' ' << cnt[3] << '\n';
//		if (l == 5 && r == 4) rep(i, 1, n) cout << cnt[a[]] 
		if (r + 2 <= n && a[r+1]==a[r+2] && !cnt[a[r+1]]) {
			cnt[a[r+1]] += 2;
			r += 2;
		} else {
//			cout << "*";
			maxx = max(maxx, r - l + 1);
			if (a[r+1]!=a[r+2] && r + 2 <= n) {//防止数组越界 
//			cout << '&';
				while (l <= r) {
					cnt[l++]--;
				}
				l += 2;
				r = l - 1;
			} else if (cnt[a[r+1]]){
				do {
					cnt[a[l]] -= 2;
					l += 2;
				}while (a[l-1] != a[r+1]) ;
			} else {
//				cout << '(';
				break;
			}
			
		}
	} 
	cout << maxx;
	return 0;
}

提出情報

ジャッジ結果