Submission #943486

#	Time	Username	Problem	Language	Result	Execution time	Memory
943486		Tuanlinh123	Lamps (JOI19_lamps)	C++17	100 / 100	77 ms	9712 KiB

lamp

#include<bits/stdc++.h>
#define ll int
#define pll pair<ll, ll>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ld long double
#define sz(a) ((ll)(a).size())
using namespace std;

const ll inf=1e9;
ll a[1000005], b[1000005], dp[2][3][2];
ll costk[2][2]={{0, 1}, {0, 0}}, costj[3][3]={{0, 1, 0}, {1, 0, 0}, {1, 1, 0}};
ll read(){char c; cin >> c; return c-'0';}
void upd(ll a, ll& b) {b=min(a, b);}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    ll n; cin >> n;
    for (ll i=1; i<=n; i++) a[i]=read();
    for (ll i=1; i<=n; i++) b[i]=read();
    for (ll i=0; i<2; i++)
        for (ll j=0; j<3; j++)
            for (ll k=0; k<2; k++)
                dp[i][j][k]=inf;
    dp[0][2][0]=0;
    for (ll i=1; i<=n; i++)
    {
        ll c=i&1, p=(i^1)&1;
        for (ll j=0; j<3; j++)
            for (ll k=0; k<2; k++)
                dp[c][j][k]=inf;
        for (ll j=0; j<3; j++)
            for (ll k=0; k<2; k++)
                for (ll jn=0; jn<3; jn++)
                    for (ll kn=0; kn<2; kn++)
                        upd(dp[p][j][k]+costj[j][jn]+costk[k][kn], dp[c][jn][kn]);
        for (ll j=0; j<3; j++)
            for (ll k=0; k<2; k++)
                if (((j<2?j:a[i])^k)!=b[i])
                    dp[c][j][k]=inf;
    }
    ll ans=inf;
    for (ll j=0; j<3; j++)
        for (ll k=0; k<2; k++)
            ans=min(ans, dp[n&1][j][k]);
    cout << ans;
}

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