Submission #488460

#	Time	Username	Problem	Language	Result	Execution time	Memory
488460		Theo830	Lamps (JOI19_lamps)	C++17	100 / 100	180 ms	145376 KiB

lamp

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e9+7;
const ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ii,ll>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
ll dp[1000005][3][2];
string a,b;
ll n;
ll solve(ll idx,ll j1,ll j2){
    if(dp[idx][j1][j2] != -1){
        return dp[idx][j1][j2];
    }
    if(idx == n){
        return 0;
    }
    ll ans = INF;
    f(k1,0,3){
        f(k2,0,2){
            char v = a[idx];
            if(k1){
                v = k1 - 1 + '0';
            }
            if(k2){
                v = ((v - '0') ^ 1) + '0';
            }
            if(b[idx] == v){
                ans = min(ans,solve(idx+1,k1,k2) + (k1 != j1 && k1 != 0) + (k2 != j2 && k2 != 0));
            }
        }
    }
    return dp[idx][j1][j2] = ans;
}
int main(void){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin>>n;
    cin>>a>>b;
    memset(dp,-1,sizeof dp);
    cout<<solve(0,0,0)<<"\n";
}

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