Submission #203031

#	Time	Username	Problem	Language	Result	Execution time	Memory
203031		dimash241	Lamps (JOI19_lamps)	C++17	100 / 100	76 ms	4552 KiB

lamp

//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")

//# include <x86intrin.h>
# include <bits/stdc++.h>

# include <ext/pb_ds/assoc_container.hpp>
# include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;
 
template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define For(i,x,y)  for (ll i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (ll i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

inline void Input_Output () {
	//freopen(".in", "r", stdin);
   //freopen(".out", "w", stdout);
}

const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;                                          
const int M = 22;
const int pri = 997;
const int Magic = 2101;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
int n;
string s, t;
int dp[33];

void upd (int &a, int b) {
	if (a > b) a = b;
}

char op (int j, char c) {
	if (2 <= j && j <= 3) c = '0';
    if (4 <= j && j <= 7) c = '1';
    if (8 <= j && j <= 9) c = '0';
    if (j & 1) c = char('0'+(1-(c-'0')));
    return c;
}

void process () {
	for (int i = 1; i < 10; i += 2) upd(dp[i-1], dp[i]); // remove toggle 
    for (int i = 8; i <= 9; i ++) upd(dp[i-4], dp[i]); // remove white 
    for (int i = 6; i <= 7; i ++) upd(dp[i-4], dp[i]); // remove black
    for (int i = 4; i <= 5; i ++) upd(dp[i-4], dp[i]); // remove black 
    for (int i = 2; i <= 3; i ++) upd(dp[i-2], dp[i]); // remove white 
    
    for (int i = 2; i <= 3; i ++) upd(dp[i], dp[i-2]+1); // add white 
    for (int i = 4; i <= 5; i ++) upd(dp[i], dp[i-4]+1); // add black 
    for (int i = 6; i <= 7; i ++) upd(dp[i], dp[i-4]+1); // add black
    for (int i = 8; i <= 9; i ++) upd(dp[i], dp[i-4]+1); // add white 
    for (int i = 1; i < 10; i += 2) upd(dp[i], dp[i-1]+1); //toggle add
}


int main () {
   	SpeedForce;

   	cin >> n;
   	cin >> s >> t;
	for (int j = 1; j <= 10; ++j) dp[j] = inf;
	for (int i = 0; i < n; i ++) {
		process();
		for (int j = 0; j < 11; ++j)
			if (op(j, s[i]) != t[i])
				dp[j] = inf;
	}

	cout << *min_element(dp, dp + 11) << '\n';

   	return Accepted;
}

// B...a

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 4 / 4
• Subtask 4: 49 / 49