Submission #866750

#	Time	Username	Problem	Language	Result	Execution time	Memory
866750		browntoad	Lamps (JOI19_lamps)	C++14	100 / 100	16 ms	16984 KiB

lamp

#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast", "unroll-loops")
using namespace std;
#define ll long long
//#define int ll
#define FOR(i,a,b) for (int i = (a); i<(b); i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n+1)
#define RREP(i,n) for (int i=(n)-1; i>=0; i--)
#define RREP1(i,n) for (int i=(n); i>=1; i--)
#define f first
#define s second
#define pb push_back
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)(x.size())
#define SQ(x) (x)*(x)
#define pii pair<int, int>
#define pip pair<int, pii>
#define pdd pair<double ,double>
#define pcc pair<char, char>
#define endl '\n'
//#define TOAD
#ifdef TOAD
#define bug(x) cerr<<__LINE__<<": "<<#x<<" is "<<x<<endl
#define IOS()
#else
#define bug(...)
#define IOS() ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#endif

//const ll inf = 1ll<<60;
const int inf = (1ll<<30);
const ll mod = 998244353;
const ll maxn=1e6+5;
const ll maxm=5e4+5;
const double PI=acos(-1);

ll pw(ll x, ll p, ll m=mod){
    ll ret=1;
    while (p>0){
        if (p&1){
            ret*=x;
            ret%=m;
        }
        x*=x;
        x%=m;
        p>>=1;
    }
    return ret;
}

ll inv(ll a, ll m=mod){
    return pw(a,m-2,m);
}
int dp[maxn][3];
bool chan[maxn][3];
int n;
signed main(){
    IOS();
    cin>>n;
    string a, b; cin>>a>>b;
    a = '0'+a; b = '0'+b;
    dp[0][0] = 1;
    dp[0][1] = inf;
    dp[0][2] = 0;
    REP1(i, n){
        bool x = a[i]-'0', y = b[i]-'0';
        chan[i][0] = (y!=0);
        chan[i][1] = (y!=1);
        chan[i][2] = (x!=y);
        REP(j, 3){
            dp[i][j] = inf;
            REP(l, 3){
                dp[i][j] = min(dp[i][j], dp[i-1][l] + (j!=2 && l!=j) + (!chan[i-1][l] && chan[i][j]));
            }
        }
    }
    cout<<min({dp[n][0], dp[n][1], dp[n][2]})<<endl;
}

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